The length of a rectangle is 6 cm more than three times the width. The area of the rectangle is 144 cm^2. What are the new dimensions of the rectangle?

Question

for the 144cm^2 that means 144 cm squared. 

Answer 1

L=6+3W  and   L*W=144

                      W=144/L

L=6+3*144/L

L=6+432/L    multiply by L

L^2=6L+432

L^2-6L-432=0

(L-24)(L+18)=0

L=24 or L=-18 

∴L=24

and W=144/24

      W=6