Question

A rectangle's is 8cm more than three times its width. If the perimeter is 128 cm, find the length

Answer 1

Hello!

To solve this we will use substitutions and a system of equations where L= length and w=width.

128=2L+2w
L=8+3w

We will substitute L with what it says it equals in the second equation.

128=2(8+3w)+2w
128=16+8w
112=8w
14=w

Now we find the length in the second equation.
L=8+42
L=50
Now we check the length and width in the original equation.
128=100+28
128=128

The length is 50 cm, and the width is 14.

Hope this helps!