Find the perimeter of a rectangle if the area is 40.5 square meters and the length is twice the width

Question

Word problem for college algebra the perimert must be in meters

Answer 1

A = l x w

l = 2w

 

40.5 = 2w x w = 2w²

 

2w² = 40.5

w² = 20.25

w = 4.5

 

l = 2(4.5) = 9

 

P = 2l + 2w = 2(9) + 2(4.5) = 3(9) = 27

 

Boom.

Answer 2

Translate "the length is twice the width" to L= 2W then substitute that in the area formula A=LxW

 

A = L x W

40.5 = 2W x W

40.5 = 2w^2          divide both sides by two

/2       /2

20.25 = w^2          take the square root of both sides

4.5 = w

 

 

Now that you know the width is 4.5, double that to find the length [which is 9].

 

You can find the perimeter using the equation 

P = 2L + 2W

P = 2(9) + 2(4.5)

P = 18 + 9

P = 27