Question 921846

w=L-8
A=240
240=wL
240=L(L-8)
240=L^2-8L
L^2-8L-240=0
(L-20)(L+12)=0
((L-20)(L+12))/(L+12)=0/(L+12)
L-20=0
L=20
w=20-8
w=12