Question

The perimeter of a rectangle is 86 cm. The length is 7 cm more than the twice the width. What is the length of the rectangle? Fill in the blank below with a number answer (not words). length​

Answer 1

31cm

Explanation:

First, we need to set up the equations

perimeter is equal to 2 times the width plus 2 times the length

p=2w+2l

86=2w+2l

then you set up what the length is

length is equal to 2 times the width plus 7

l=2w+7

then use substitution to find the width

86=2w+2(2w+7)

86=6w+14

72=6w

12=w

then you take the width and plug it into the length

l=2(12)+7

l=31

thus the length is 31cm