Question

The length of a rectangle is 5 inches more than three times the width. The perimeter is 90 inches. Find the length and width

Answer 1

L=length W=width
The relation --> L=3W+5
2L+2W=perimeter of the rectangle
>now substitute 3W+5 for L, so that you are dealing with like terms
2(3W+5)+2W=permiteter
>we already know that the perimeter is 90, so make that equal to the above expression
Step by step calculation:
2(3W+5)+2W=90
6W+10+2W=90
8W+10=90
8W=80
*w=10

now you can sub W=10 into the original relation for L
L=3W+5
L=3(10)+5
L=30+5
*L=35