Question

PLEASE HELP!!

The length of a rectangle is 4 less than three times its width. The perimeter is 72 feet. Find the dimensions of the rectangle.

Answer 1

Let x = the width
:
It says,"The length of a rectangle is 4 less than 3 times the width." write that as:
L = 3x - 4
:
If the perimeter is 40, find the dimensions of the rectangle.
:
We know: 2L + 2W = 40
:
Substitute (3x-4) for L and x for W
2(3x-4) + 2x = 40
:
6x - 8 + 2x = 40; Multiplied what's inside the brackets
:
6x + 2x = 40 + 8; do some basic algebra to find x; (added 8 to both sides)

:
8x = 48
:
x = 48/8
:
x = 6 which is the width
:
It said that L = 3x - 4, therefore:
L = 3(6) - 4
L = 18 - 4
L = 14; is the length
:
Check our solutions in the perimeter:
2(14) + 2(6) =
28 + 12 = 40

Answer 2

length= 3x-4
width= x
perimeter= 72 feet
2(3x-4)+2x=72
6x-8+2x=72
8x-8=72
8x=80
x=10
The width is 10 and the length is 26.

Hope this helps!