hi everyone today is world environment day please give me 100 to 200 word eassy on environment to save nature can anyone help this ~ ​

Hi Everyone Today Is World Environment Day Please Give Me 100 To 200 Word Eassy On Environment To Save

Answers

Answer 1
♨ANSWER♥

The conditions or surroundings in which we all live is called the environment. The main elements of the environment are air, water, temperature, weather conditions and more.

The environment is the base of the life cycle. It is the most precious gift of nature. But now our environment is in danger. Saving the environment is very important for living a comfortable life. It is the biggest challenge for humans to revert the environment to its real state. But nothing is impossible.

We need to take some steps immediately in order to save the environment and revert it back to its original form. Using natural resources efficiently is a powerful way to save our environment.

♥happy environment day♥

...hope this helps...

_♡_mashi_♡_


Related Questions

ITS URGENT I WILL YOU GIVE BRAINLEST(if you are the first and the best)!!!

Answers

Answer:

2 Hours

Step-by-step explanation:

First you have to add up all the points which would be;

1 1/2 + 1 1/2+ 2 1/2+ 2 1/2= 8 hours

Then you have to divide by how many points to find the average;

8 hours divided by 4 points= 2 hours average

In total, she will practice 2 hours every day


Gerald will be finishing his payments on his 5-year, $45,000 student loan and wants to know the amount of interest that he
paid over the course of the loan. The student loan has a 4.1% fixed interest rate that is compounded monthly. Calculate the
total amount of interest Gerald paid, rounding to the nearest cent.

Answers

Answer: 538

Step-by-step explanation: en verdad no sé pero eso fuelo que me salio

If f(x)=x2−4x+4 , then f(3)=

Answers

Answer:

f(3) = 1

Step-by-step explanation:

substitute x = 3 into f(x) , that is

f(3) = 3² - 4(3) + 4 = 9 - 12 + 4 = 1

Answer:

1

Step-by-step explanation:

Substitute 3 for x in your equation leaving you with (3)^2-4(3)+4.

9-12+4

-3+4=1

Calculate the area of the alarm clock.

Answers

Given the diameter of the surface of the clock, the area of the surface of the alarm clock is 3846.5cm².

What is the area of the alarm clock?

Note that: Area of a circle is expressed as;

A = πr²

Where r is radius and π is constant pi ( π = 3.14 )

Given that;

Diameter d = 70cm Radius r = d/2 = 70cm/2 = 35cmArea = ?

A = πr²

A = 3.14 × ( 35cm )²

A = 3.14 × 1225cm²

A = 3846.5cm²

Therefore, given the diameter of the surface of the clock, the area of the surface of the alarm clock is 3846.5cm².

Learn more about area of circle here: https://brainly.com/question/22964077

#SPJ1

You are trying to bulk and gain muscle. Your trainer says your daily calorie intake should increases based on hours you spend exercising and can be represented by the following equation: T=2000+500h.

Answers

a) T - Calories, 2000 - Minimum calories, 500 - Additional calories per exercise hour, b) We should consume 3500 calories to spend three hours exercising.

How to analyse a linear function of calorie gain in terms of the exercise time

In this question we have a linear function where the independent variable is the exercise time (h), in hours, and the dependent variable is the calorie gain (T), in calories. The constant "2000" is the minimum calorie consumption and the constant "500" represents the amount of additional calories per each hour of exercise.

Now we proceed to respond the questions of the part a):

(i) T - Amount of calories needed, (ii) 2000 - Minimum calorie consumption, (iii) 500 - Amount of additional calories per hour of exercise.

b) And lastly we calculate the amount of calories by evaluating the function:

T = 2000 + 500 · 3

T = 2000 + 1500

T = 3500

We should consume 3500 calories to spend three hours exercising.

Remark

The statement is incomplete, the complete form is shown below:

You are trying to bulk up and gain muscle. Your trainer says that your daily calorie intake should increase based on the hours you spend exercising and can be represented by the following equation: T = 2000 +  500 · h

a) What does each part of this expression represent? (i) T = , (ii) 2000, (iii) 500, (iv) h

b) If you spend 3 hours exercising, how many calories should you consume?

To learn more on linear functions: https://brainly.com/question/21107621

#SPJ1

Solve the following linear equation:
3(2x + 12) = 2(2x - 10)

Answers

Answer: x = -28

Step-by-Step Explanation:

3(2x + 12) = 2(2x - 10)
3 * 2x + 3 * 12 = 2 * 2x - 2 * 10
6x + 36 = 2 * 2x - 2 * 10
6x + 36 = 4x - 20
6x - 4x + 36 = -20
2x + 36 = -20
2x = -20 - 36
2x = -56
x = -56/2
=> x = -28

Therefore, x = -28
Hey! I decided to write it for you.
Step 1: Distribute
Step 2: Move the x to one side by simplifying
Step 3: Take a way 36 from both sides
Step 4: Divide and simplify

Question 18
Let set A = { even numbers}
set B = {odd numbers}
Find A U B

Answers

Answer: all integers

Step-by-step explanation:

[tex]A \cup B[/tex] denotes the union of the two sets, and is thus the set of all integers.

The universal set, &, and the sets A and B are defined below.
= {3, 4, 6, 8, 9, 12, 15, 16, 20}
A = {6, 9, 12, 15}
B = {multiples of 4}
Write down all the elements of AB'.

Answers

Answer:

wedg

Step-by-step explanation:

ed

Find a3, a4, and a5.
a₁ = 5
a₂ = 2
an =-2an -1 + an-2

Answers

Answer:

A1 5×3 = 15

A2 = 2×4= 8

an=I don't know that one

Find the 66th term in the following
arithmetic sequence:
-92, -85, -78, -71, ...

Answers

Answer: 363

Step-by-step explanation:

The common difference is 7, so the explicit formula is [tex]a_{n}=-92+7(n-1)[/tex].

Substituting in n=66,

[tex]a_{66}=-92+7(66-1)=\boxed{363}[/tex]

Find the circumference of a circle that has a diameter of 2 ft. Use 3.14 for pi.

5.14 ft
6.28 ft
12.56 ft
7.14 ft

Answers

Answer:

6.28 ft

Step-by-step explanation:

using the formula [tex]\pi d[/tex] to find the circumference of the circle, you substitute the numbers. 3.14(2). 3.14 x 2 = 6.28 hence the answer

Find x. Round your answer to the nearest tenth of a degree.
36
X
19
+

Answers

Answer: 36.9

Step-by-step explanation:

Date:
Name:
Refocus
Directions: Solve the problems by building the figure with algebra tiles and writing an equation.
A rectangle has a length that is twice the width. The perimeter of the rectangle is 12 feet.
What is the width? What is the length?
Equation:
Width:
Length:

Answers

Answer:

Equation: 2w + 2(2w) = 12

width = 2

length = 4

Step-by-step explanation:

Width is w

Length is 2 * width = 2w

Perimeter is 2w + 2l

Substitute 2w for L.

Perimeter is now 2w + 2(2w) = 12

Distribute the 2 to the parentheses.

2w + 4w = 12

Combine Like terms

6w = 12

Divide by 6 to solve for w.

w = 2

If w = 2, then the length = 4.

A line intersects the points (3,6) and (5, -4). m=-5 write an equation in point-slope form using the point (3,6)y - [?] = __ (x -__)

Answers

Answer:

  y -6 = -5(x -3)

Step-by-step explanation:

The point-slope form of the equation for a line is ...

  y -k = m(x -h) . . . . . . line with slope m through point (h, k)

__

substituting given values

You have been given ...

  m = -5

  (h, k) = (3, 6)

Putting the given values into the point-slope form gives the equation you want:

  y -6 = -5(x -3)


Find the fist 4 terms of a geometric series with first term of 8 and the sum to infinity of 12

Answers

Step-by-step explanation:

the sum of an infinite geriatric series with |r| < 1 is

s = a1/ (1 - r)

in our case we have

a1 = 8

12 = 8/(1 - r)

12(1 - r) = 8

1 - r = 8/12 = 2/3

-r = -1/3

r = 1/3

so, the first 4 terms (I added a5 too, just in case your teacher meant the NEXT 4 terms) are

a1 = 8

a2 = a1 × 1/3 = 8/3

a3 = a2 × 1/3 = 8/9

a4 = a3 × 1/3 = 8/27

a5 = a4 × 1/3 = 8/81

...

Answer:

[tex]8,\quad \dfrac{8}{3},\quad \dfrac{8}{9},\quad\dfrac{8}{27}[/tex]

Step-by-step explanation:

Sum to infinity of a geometric series:

[tex]S_\infty=\dfrac{a}{1-r} \quad \textsf{for }|r| < 1[/tex]

Given:

[tex]a[/tex] = 8[tex]S_\infty[/tex] = 12

Substitute given values into the formula and solve for [tex]r[/tex]:

[tex]\implies 12=\dfrac{8}{1-r}[/tex]

[tex]\implies 1-r=\dfrac{8}{12}[/tex]

[tex]\implies r=1-\dfrac{8}{12}[/tex]

[tex]\implies r=\dfrac{1}{3}[/tex]

General form of a geometric sequence: [tex]a_n=ar^{n-1}[/tex]

(where a is the first term and r is the common ratio)

Substitute the found values of [tex]a[/tex] and [tex]r[/tex]:

[tex]\implies a_n=8\left(\dfrac{1}{3}\right)r^{n-1}[/tex]

The first 4 terms:

[tex]\implies a_1=8\left(\dfrac{1}{3}\right)r^0=8[/tex]

[tex]\implies a_2=8\left(\dfrac{1}{3}\right)r^1=\dfrac{8}{3}[/tex]

[tex]\implies a_3=8\left(\dfrac{1}{3}\right)r^2=\dfrac{8}{9}[/tex]

[tex]\implies a_4=8\left(\dfrac{1}{3}\right)r^3=\dfrac{8}{27}[/tex]

Which of the following discribe an angle with a vertex at y

Answers

Answer:

The angle is referred to as a ∠ZYX angle, or ∠XYZ angle, because of the overall positioning. Think of it this way, you have a triangle with 3 angles. You have point X the high point, point Y the farthest point out, and point Z which makes the triangle complete. Connect these, and your angle becomes ZYX / XYZ.

Hope this helps!

9) A furniture store is having a spring sale-15% off of everything in the store.
What is the price of a table that regularly costs $159.98 if it is bought on sale?

Answers

Answer:

$135.98

Step-by-step explanation:

15% of $159.98 = 0.15 × $159.98 = $24.00

$159.98 - $24.00 = $135.98

find the slope of the line that passes through (9,-3) and (9,-8)

Answers

Answer:

The line has no slope. I hope this helps

Find the probability of rolling a 66 -sided dice and getting a number that is a divisor of 2020

Answers

Answer:

2/3 or 0.66 repeated

Step-by-step explanation:

Since 2022 is only divisible by 1,2,4, and 5, the probability of getting a number that is a divisor of 2020 is 4/6, simplified to 2/3 or %0.66.

A particle moves along line segments from the origin to the points (2, 0, 0), (2, 5, 1), (0, 5, 1), and back to the origin under the influence of the force field
[tex]F(x,y,z) = z^2i+5xyj+2y^2k[/tex]
Use Stokes Theorem to find the work done:

Answers

A particle moves along line segments from the origin to the points, work done is mathematically given as

W=184.5units

What is the solution of an equation that matches the model.?

Considering line segments from (0,0,0)origin to (2,0,0) , (2,5,1) and (0,5,1) under the infulence of force

Generally,  the equation for force is mathematically given as

F = z2i + 5xyj + 2y2k

Therefore, Considering u*v

[tex]u * v = (u_1j+u_2j+u_3k) * (v_1i+v_2j+v_3k)[/tex]

[tex]u* v = u_1v_1(i * i) + u_1v_2(i * j)+u_1v_3(i * k) + u_2v_1(j * i) + u_2v_2(j * j)+u_2_3(j* k) + u_3v_1(k * i) + u_3v_2(k * j)+u_3v_3(k * k)[/tex]

Where

[tex]i * i = j *j=k * k=0[/tex]

Hence

[tex]u* v = u_1v_2k-u_1v_3j-u_2v_1k+u_2v_3i +u_3v_1j - u_3v_2i[/tex]

[tex]u = (u_1,u_2,u_3) = (0,5,1)\\\\v = (v_1,v_2,v_3) = (-3,0,0)[/tex]

The normal equation formed

-2y + 15z = 0

z= (1/5)y

Considering the level surface and differential surface area

h(x,y,z) = -y + 5z =0

[tex]dS = |grad(h)| dA[/tex]

In terms of the x and y coordinates of (2,0,0) and (2,5,1) and (0,5,1), we can state that the ranges are 0 to 3 and 5 respectively we have

[tex]0 \leq x \leq 2 \ and \ 0 \leq y \leq 5[/tex]

Using strokes theorem to evaluate

[tex]F = z2i + 5xyj + 2y2k[/tex]

[tex]curl \ F = 4yi+2zj+5yk = (4y,2z,5y)[/tex]

[tex]curl \ F * nds= \frac{1}{5}(-2z + 25y)\ dy \ dx[/tex]

In conclusion, The work done is

[tex]W=\int _CF *dr[/tex]

[tex]\int _C F * dr = \int \int curl \ F * n ds[/tex]

[tex]\int _C F *dr = \frac{123}{2}\int_0^3 \ dx[/tex]

[tex]\int _C F * dr = \frac{123*3}{2}[/tex]

W= 184.5units

Read more about work done

https://brainly.com/question/25573309

#SPJ1

How many classrooms would be necessary to hold 1,000,000 inflated balloons? (Assume one balloon is about 1 ft3 and a typical classroom is about 35 ft × 50 ft × 15 ft. Round your answer to the nearest number of classrooms.)

Answers

38 classrooms (to the nearest whole number)

One balloon = 1 cube ft. Using this value and multiplying it by 1,000,000, we can find how much space all of these would take up. Since 1 times anything is just the unchanged value,
• a million inflated balloons = 1000000 ft^3.

The classroom has dimensions 35, 50, and 15 ft. We can use these values to find the classroom’s volume. The equation for Volume of a rectangular prism: V = lwh, where l is length, w is width, and h is height. Substitute given dimensions into this equation:
• V = 35*50*15 = 26250 ft^3.

now, what times 26250 will equal 1000000? Well, let’s set up an equation and solve for x, the number of classrooms.
• 26,250x = 1,000,000. Divide both sides by 26250 to get x alone:
• x = 38.0952.

Approximately 38 classrooms are necessary to hold 1,000,000 inflated balloons.

Check: when x is 38: 26,250(38) = 997,500 ft^3. When x is 39: 26,250(38) = 1,023,750 ft^3. x = 38 is more accurate.
**(I will note, however, that I’m not sure if you’re instructed to round according to the decimal rules or round UP a whole number because that extra .0952 needs to be included).

To hold 1,000,000 inflated balloons,

38 classrooms are needed.

What is volume?

In three-dimensional space,

the amount of space taken by an object is the volume of that object.

The volume of the cubic,

= length x width x height

Given:

The dimensions of the normal classroom are 15 ft × 50 ft × 35 ft.

The volume of the classroom,

= 15 ft by 50 ft by 35 ft.

= 26250 cubic feet.

The number of classrooms,

= 1,000,000 / 26250

Simplifying the fraction,

we get,

= 38.09

≈ 38 to the nearest whole number.

Therefore, 38 classrooms are required.

To learn more about the volume;

https://brainly.com/question/23477586

#SPJ2

What is the slope of the line that cuts through the points (1, 2) and (5, 4)? a. 2 c. One-half b. -2 d. Negative one-half Please select the best answer from the choices provided A B C D

Answers

The slope of the line is 1/2 or one-half if the line that cuts through the points (1, 2) and (5, 4) option (c)  One-half is correct.

What is the slope?

The ratio that y increase as x increases is the slope of a line. The slope of a line reflects how steep it is, but how much y increases as x increases. Anywhere on the line, the slope stays unchanged (the same).

[tex]\rm m =\dfrac{y_2-y_1}{x_2-x_1}[/tex]

We have a line that cuts through the points (1, 2) and (5, 4).

The slope of a line:

[tex]\rm m =\dfrac{4-2}{5-1}[/tex]

m = 2/4

m = 1/2

Thus, the slope of the line is 1/2 or one-half if the line that cuts through the points (1, 2) and (5, 4).

Learn more about the slope here:

brainly.com/question/3605446

#SPJ1

Which statement is true?

a.All rectangles are parallelograms. Parallelograms have 2 pairs of parallel sides. Therefore, all rectangles have 2 pairs of parallel sides.

b.Only some rectangles are parallelograms. Parallelograms have exactly 1 pair of parallel sides. Therefore, only some rectangles have exactly 1 pair of parallel sides.

c.Only some rectangles are parallelograms. Parallelograms have 2 pairs of parallel sides. Therefore, only some rectangles have 2 pairs of parallel sides.

d.All rectangles are parallelograms. Parallelograms have exactly 1 pair of parallel sides. Therefore, all rectangles have exactly 1 pair of parallel sides.

Answers

Answer:

All rectangles are parallelograms. Parallelograms have 2 pairs of parallel sides. Therefore, all rectangles have 2 pairs of parallel sides.

Step-by-step explanation:

OK so I don't know why but I enjoy giving away points, so if anyone has the right answer then please put it in, if not please DO NOT put it in, this is for helping others, not for greed.
Lakima has a spinner divided into 5 equal sections that are labeled 1 though 5. She wants to compare the theoretical probability and the experimental probability of spinning an odd number. She spins the spinner 6 times and records the results in this list. {2, 4, 1,​ 5, 3,​ 4} Drag and drop the answers into the boxes to correctly complete the sentences. The theoretical probability of spinning an odd number is equal to . The experimental probability of spinning an odd number is equal to Response area. Therefore, the theoretical probability of spinning an odd number is the experimental probability of spinning an odd number.

Answers

The theoretical probability of getting an odd number is 0.6, but the experimental probability was 0.5.

What is the theoretical probability?Total of numbers in the spinning wheel: 5Total of odd numbers: 3 (1,3,5)

Probability of getting an odd number: 3/5 = 0.6 or 60%

What is the experimental probability?Number of times the wheel was spinned: 6 timesNumber of times she got an odd number: 3 times

6 times = 1003 times =   x

x = 3 x 100/ 6x = 50% or 0.50

What can be concluded?

The experimental probability is lower than the theoretical probability.

Learn more about experimental probability in: https://brainly.com/question/15729871

#SPJ1

Answer:

Answer in pic below

Step-by-step explanation:

The speed of an object in space is shown in the graph.


A graph titled Speed of Object has Time in Minutes on the x-axis and Distance in Miles on the y-axis. A line goes through points (0.2, 3) and (0.4, 6).

What is the slope of the line?
A) 10
B) 15
C) 20
D) 25

Answers

The slope of the linear equation is 15, so the correct option is B.

How to get the slope of the line?

A linear equation can be written as:

y = a*x + b

Where a is the slope and b is the intercept.

For a line that passes through the points (x₁, y₁) and (x₂, y₂), the slope can be written as:

[tex]a = \frac{y_2 - y_1}{x_2 - x_1}[/tex]

Here we have the two points (0.2, 3) and (0.4, 6), so the slope is:

[tex]a = \frac{6 - 3}{0.4 - 0.2} = 15[/tex]

So the slope of the line is 15, which means that the correct option is B.

If you want to learn more about linear equations:

https://brainly.com/question/1884491

#SPJ1

Solve for x: -8 < 3x + 1 ≤ 13

Answers

Answer: If you’re doing algebra, -3<x or x<_4.

Another answer is -3<x<_4

Answer:

-3 < x <_4

Step-by-step explanation:

-8 < 3x+1 <_13

First solve for the left side: -8 < 3x + 1

Subtract 1 from each side

-9 < 3x

Divide each side by 3

-3 < x

Solve for the right side: 3x+1 <_13

Subtract 1 from each side

3x <_ 12

Divide each side by 3

x<_4

Put it together for your answer

-3 < x <_4

Divide x cubed minus 3 x squared minus 10 x + 24 by x minus 2. Step 1 - Fill in the missing number: A vertical line and horizontal line combine to make a L shape. There is one row of entries in the shape including 1, negative 3, negative 10, 24. On the outside to the left of the L shape is k. k = Step 2 - Fill in the missing number: A vertical line and horizontal line combine to make a L shape. There is one row of entries in the shape including 1, negative 3, negative 10, 24. On the outside to the left of the L shape is 2 and to the outside below 1 is a. a = ⇒ 1 Step 3 - Fill in the missing numbers: A vertical line and horizontal line combine to make a L shape. There are two rows of entries in the shape. The first row includes 1, negative 3, negative 10, 24. The second row includes blank, b, d, blank. On the outside to the left of the L shape beside row 1 is 2. On the outside below the L shape in the first column is 1 and in the second column is c. b = c = d =

Answers

The dividend that's represented by the synthetic division is 2x³ + 10x² + x + 5.

How to depict the dividend?

From the information, given that the vertical line and a horizontal lines combined to form the L shape.

Row 1 has entries 2, 10, 1, 5.

Row 2 has entries -10, 0, -5.

In this situation, entry -5 is outside to the let of the shape.

Here, the dividend that's represented by the synthetic division is 2x³ + 10x² + x + 5.

Learn more about division on:

brainly.com/question/26410027

#SPJ1

Answer:

step 1: 2 Step 2: 1

Step-by-step explanation:

Step 3: 2, -1, -2

Complete the division. The remainder is 0. The quotient is x^2 - x - 12.

what is the volume of the rectangular prism each is 1/3

Answers

Answer:

The answer is 7

Step-by-step explanation:

To find the volume you multiply the width, height, and the length.

Length= 7/3

width= 3/3

height= 9/3

When you multiply you then have to simplify which is 7/1 or 7.

Mark this correct to help me gain!!

What is the equation of the line that passes through the point (6, 1) and has a slope
of -1/2

Answers

Answer:

y = 6x + [tex]\frac{-1}{2}[/tex]

Step-by-step explanation:

I think take this with a grain of salt

please help anyone i really need it ​

Answers

Answer:

Median: 21

Eric took the longest

Ed took 18 minutes longer than Mike

Oscar took the shortest amount of time to solve the puzzle

Step-by-step explanation:

The median is the middle amount of the numbers, line them up from smallest to largest and find the number in the middle...the largest number is the person who took the longest...subtract Ed's score (25) from Mike's score (4) to get the answer...and the smallest number is the person who took the shortest amount of time

Other Questions
For which groups did president clinton make repeated attempts to broker a peace agreement?. Lin surveyed a class of sixth-graders asking how many hours they spend online every month. MATH!!! 15 points;)) find the surface area of the pyramidplease answer correctly & check your work... Find out the sum by suitable arrangement.1 + 2 + 3 + 4 + 5 + 95 + 96 + 97 + 98 + 99 Simplify: -4x542x5Enter the original expression if it cannot besimplified.Enter the correct answer.000008Clear all+?DONE What is 3.9443.9443, point, 944 rounded to the nearest hundredth? Which addtional rights in floridas declaration of rights are not included in the us bill of rights Which two details helps to build tension in the passage Which argument is most clearly making an ad hominem fallacy?O A. Dr. Rodriguez recommends surgery, but I oppose slicing peopleopen at a whim.OB. If we call Star Wars a fantasy, we might as well call Harry Potterscience fiction.OC. My opponent's proposal should be ignored because she is aknown liar and cheat.D. Dogs are superior to cats, birds, fish, and other pets because oftheir superiority. If and are the zeros of the quadratic polynomial f(x) = 6x+x-2, then the value of1. +2. 1/+1/Can Someone Answer This Quick Thank You please help... Find the volume of pyramid that has a square base. ( -16 + 12 ) ( -4 + 2 ) = What is the Answer 3. Which of the following provides the best description of active transport ofmaterials across the cell membrane?A:Active transport does not require energy and moves materials from areas ofrelatively higher to lower concentration.B:Active transport requires energy and moves materials from areas ofrelatively lower to higher concentration.C:Active transport does not require energy and moves materials from areas ofrelatively lower to higher concentration.D:Active transport requires energy and moves materials from areas ofrelatively higher to lower concentration. Which of the following is not one of the four things that all organisms need to survive?A. waterB. airC. a source of energyD. the ability to move which of the following was not an important reason that europeans colonized africa? a. europeans believed they were superior and it was duty to civilize the african continent b. europeans nations wanted to show their powers by increasing the amount of territory they controlled. c. europeans wanted to spread muslim beliefs throughout the continent of africa d. europeans nations wanted to profit from the vast natural resources in africa The main reason the free-soilers came to kansas in the 1800s was to ensure that the people of kansas could be enslavers. to ensure that kansas voted to become a free state. to help free black people move into the territory. to claim the free land they were promised in kansas. answer this so I can give you some 85 points Which is the graph of 5 log (x + 3)? pairs of _____ are usually at the top of each set of facing pages Read the sentence:The new classmate walked into her new school, hoping that none of the other kids would be unfriendly.What does the prefix un- do to the word friend?