Question 235041
Good Afternoon,

In response to your question:

“the length of a rectangle is 4 feet less than 3 times its width. the perimeter is 16 feet. what is its length.”

Step one:  Write the sentence in equation form.  Lets call the width W and the length L

If it’s easier translate one part of the sentence at a time starting with the multiplication first.  So the first sentence now reads:

“The length of a rectangle is 4 feet less than 3W.”

Now translate the rest:

L=3W-4

For the second sentence you need the formula for the perimeter W+L=perimeter= 16 feet.

Now there are 2 equations with two unknowns:

L=3W-4     (1)
2(W+L)=16    (2)

Substitute for L in equation (2):

W + (3W-4) =16,
Which simplifies to:
W=3
Substitute for this value of W in either equation (1) or (2). If I put it in equation (1)  I get:

L=3(3) -4=5

Check results:

Substitute for L=5 and W=4 into equation (2) for the perimeter:

2(3+5)=16
Since the left-hand-side is equal to the right-hand-side this is the correct answer.

Good Luck,

Selma from Rent-A-Whiz.   A new online tutoring and homework help resource.  For more details visit us at www.rentawhiz.com.