Ask question

Ask question

All categories

3 years ago

10

A rectangle has perimeter 78 cm and length 32 cm. What is its width?

1 answer:

zzz [600]3 years ago

8 0

Answer:

width = 7 cm

Step-by-step explanation:

So, to find the perimeter you multiply the width by 2, multiply the length by 2, then add them together.

P = 2L + 2W

But, we already know the perimeter and length, so we need to find the width.

78 = 2(32) + 2W

78 = 64 + 2W

-64 -64

14 = 2W

/2 /2

7 = W

So, to check your answer, plug in the width (that you just found), and the length to see if you get 78, the perimeter.

P = 2L + 2W

P = 2(32) + 2(7)

P = 64 + 14

P = 78

So, yes, the width =7

You might be interested in

The record high January temperature in Austin, Texas, is 90 degrees F The record low January temperature is -7 degrees F, Find t

Black_prince [1.1K]

i think the answer is -97

3 0

3 years ago

Use the shell method to write and evaluate the definite integral that represents the volume of the solid generated by revolving

faust18 [17]

Answer:

$Volume = \frac{384}{7}\pi$

Step-by-step explanation:

Given (Missing Information):

$y = x^\frac{3}{2}$ ; $y = 8$ ; $x=0$

Required

Determine the volume

Using Shell Method:

$V = 2\pi \int\limits^a_b {p(y)h(y)} \, dy$

First solve for a and b.

$y = x^\frac{3}{2}$ and $y = 8$

Substitute 8 for y

$8 = x^\frac{3}{2}$

Take 2/3 root of both sides

$8^\frac{2}{3} = x^{\frac{3}{2}*\frac{2}{3}}$

$8^\frac{2}{3} = x$

$2^{3*\frac{2}{3}} = x$

$2^2 = x$

$4 =x$

$x = 4$

This implies that:

$a = 4$

For $x=0$

This implies that:

$b=0$

So, we have:

$V = 2\pi \int\limits^a_b {p(y)h(y)} \, dy$

$V = 2\pi \int\limits^4_0 {p(y)h(y)} \, dy$

The volume of the solid becomes:

$V = 2\pi \int\limits^4_0 {x(8 - x^{\frac{3}{2}}}) \, dx$

Open bracket

$V = 2\pi \int\limits^4_0 {8x - x.x^{\frac{3}{2}}} \, dx$

$V = 2\pi \int\limits^4_0 {8x - x^{\frac{2+3}{2}}} \, dx$

$V = 2\pi \int\limits^4_0 {8x - x^{\frac{5}{2}}} \, dx$

Integrate

$V = 2\pi * [{\frac{8x^2}{2} - \frac{x^{1+\frac{5}{2}}}{1+\frac{5}{2}}]\vert^4_0$

$V = 2\pi * [{4x^2 - \frac{x^{\frac{2+5}{2}}}{\frac{2+5}{2}}]\vert^4_0$

$V = 2\pi * [{4x^2 - \frac{x^{\frac{7}{2}}}{\frac{7}{2}}]\vert^4_0$

$V = 2\pi * [{4x^2 - \frac{2}{7}x^{\frac{7}{2}}]\vert^4_0$

Substitute 4 and 0 for x

$V = 2\pi * ([{4*4^2 - \frac{2}{7}*4^{\frac{7}{2}}] - [{4*0^2 - \frac{2}{7}*0^{\frac{7}{2}}])$

$V = 2\pi * ([{4*4^2 - \frac{2}{7}*4^{\frac{7}{2}}] - [0])$

$V = 2\pi * [{4*4^2 - \frac{2}{7}*4^{\frac{7}{2}}]$

$V = 2\pi * [{64 - \frac{2}{7}*2^2^{*\frac{7}{2}}]$

$V = 2\pi * [{64 - \frac{2}{7}*2^7]$

$V = 2\pi * [{64 - \frac{2}{7}*128]$

$V = 2\pi * [{64 - \frac{2*128}{7}]$

$V = 2\pi * [{64 - \frac{256}{7}]$

Take LCM

$V = 2\pi * [\frac{64*7-256}{7}]$

$V = 2\pi * [\frac{448-256}{7}]$

$V = 2\pi * [\frac{192}{7}]$

$V = [\frac{2\pi * 192}{7}]$

$V = \frac{\pi * 384}{7}$

$V = \frac{384}{7}\pi$

Hence, the required volume is:

$Volume = \frac{384}{7}\pi$

3 0

2 years ago

What's the answer for 99 help

ivann1987 [24]

This problem lacks information necessary to answer it

8 0

3 years ago

The solutions to a certain quadratic equation are x = -4 and x = 3. Write the equation in standard form below.

PolarNik [594]

Answer:

x2 +x -12=0

hope you got it

6 0

2 years ago

What is -4 3/10 - 8 3/10

nadya68 [22]

Answer:

-12 3/5

Step-by-step explanation:

-4 3/10 - 8 3/10

The signs are the same so we add and then take the sign

4 3/10 + 8 3/10

Add the whole numbers

4+8 = 12

Add the fractions

3/10 + 3/10 = 6/10

Simplify the fraction

6/10 = 3/5

Put them together

12 3/5

Add the sign

-12 3/5

4 0

3 years ago

Read 2 more answers