Question

The perimeter of a rectangle garden is 48 feet. The length is 5 times the width.

Answer 1

Hello there,
Perimeter of the rectangle=
2(l+w)

2(l+w)=48 feet
2(l+w)/2=48 feet/2
l+w=24 feet

l=5w
Next step replace l with 5w to get

5w+w=24 feet
6w=24 feet
w=4 feet
l=5w
l=5(4)
l=20 feet. As a result, the correct answer is 4ft by 20 ft or B. Hope it help!

Answer 2

I'll draw a diagram for you, so that it's easier to understand. 
First you have to understand that the perimeter is all the sides add up together.

Let's set up an equation, using l for the length, and w for the width.

5w + w = 48
Simplify
6w = 48
Divide by 6 on both sides
w = 8

Now the value we got is actually both widths (the green sides), so the width is actually 4. Which means that the length is 20. 

The answer is 4ft by 20 ft.

Hopefully this helps! If you have any more questions or don't understand, feel free to DM me, and I'll get back to you ASAP! :)