algebra 1 question

Question

The length of a rectangle is three more than double the width. If the perimeter is 84 inches, find the dimensions

Answer 1

Hi Grace,

You can use the info from Mark M. Here are some more details:

the perimeter is the sum of the sides of the rectangle. Two of the sides are the width , w and the other two sides are lengths. Since the problems says that you can use an expression for the length using 3 more than double the width or:

2w + 3 for each length.

There are 4 total sides in the rectangle, so you can write the following equation for the perimeter, P:

P= w + w + 2w + 3 +2w + 3

Combine like terms:

P= 6w+ 6

Since P is 84 inches in this problem, then:

84 = 6w + 6

Solve for w:

84-6 = 6w + 6 - 6

78 = 6w

78/6 = 6w/6

13 inches = w

The length will be 2w + 3 or:

2*13 + 3= 29 Inches

To check, the perimeter will be :

13 + 13 + 29 + 29 = 84 inches

Answer 2

w repressents the width

2w + 3 represents the length

84 = 2(w + 2w + 3)

Can you solve for w and answer?