the perimeter of a rectangle is 24. the length is three less than double the width

Question

The perimeter of a rectangle is 24. The length is three less than double the width. What is the length, width of the rectangle?

Answer 1

Perimeter of a rectangle is 2(l+w) or 2l+2w

2l+2w=24....divide all sides by 2

l+w=12

l=2w-3...substitute value of l in equation

2w-3+w=12...add

3w-3=12

   +3=+3...add

======

3w  =15...divide both sides by 3 to get w

w=5

2(5)-3=10-3=7=l

l=7,w=3

 

Answer 2

Hi Sam--

 

Call your width w

 

Call your length 2w - 3

 

So you have 2 widths, or 2w

 

And you have 2 lengths, or 2(2w-3), or 4w - 6

 

So add up your 2w plus your 4w - 6 to equal 24:

 

6w - 6 = 24.

 

Can you solve from there?

 

Hope this helps!

 

Matt in NY