Question

Gabriella needs 120 meters of fence to surround a rectangular garden.

The length of the garden is three times its width, w.

How wide is the fence?
Please try to include a Screenshot with the answer

Answer 1

15m

Explanation:

Well, she needs 120 meters, which means we already know the circumference (P). P is the sum of all sides.

The lenght (a) is 3 times the width(b).

a = 3b.

Which means if a is x then b is equal to 3x

Since P is the sum of all sides, P is equal to 2a + 2b or 2x + 2*3x = 2x + 6x = 8x

120 = 8x. We are now left with an equation that has one variable only, all we need to do is to divide 120 by 8 to find what x is equal to.

8x = 120

x = 120 / 8

x = 15

We know that width(a) is equal to x, so that's the answer.

Here's a solution you can write:

P = 120m

w = x

l = 3w = 3x

P = 2w + 2l

P = 2*x + 2*3x

P = 2x + 6x

P = 8x

8x = 120

x = 120 / 8

x = 15

w = x -> w = 15m

Answer 2

the width is 1.5meters

Explanation:

the perimeter of the fence is 120m

the perimeter= 3w+w+3w+w

120= 3w+w+3w+w

120= 8w

w=1.5m