the area of a rectangle is 72 cm^2. If the length is 6 cm more than the width, what are the dimensions of the rectangle? Solving quadratic application problems

Question

 i really need help test is later today and teacher won't help me

 

Answer 1

Length = Width+6

 

Area = W * L

 

Area = W * (W+6)

 

Multiply it out

 

Area = W^2 + 6W

 

Area=72

 

72 = W^2 + 6W

 

subtract 72 from both sides

 

0 = W^2 + 6W - 72

 

12 * 6 = 72

 

12 - 6 = 6

 

Factor it

 

0 = (W-6)(W+12)

 

W = 6 and W = -12

 

Width must be 6 cm because Width can't be negative

 

L = W+6

 

L = 6 + 6

 

L = 12 cm