Question 113765
L=3+2W
AREA=L*W
99=(3+2W)W
99=3W+2W^2
2W^2+3W-99=0
USING THE QUADRATIC EQUATION {{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}} 
YOU GET:
W=(-3+-SQRT[3^3-4*2*-99])/2*2
W=(-3+-SQRT[9+792])/4
W=(-3+-SQRT801)/4
W=(-3+-28.3)/4
W=(-3+28.3)/4
W=25.3/4
W=6.325 FOR THE WIDTH.
L=3+2*6.325
L=3+12.65
L=15.65 FOR THE LENGTH.
PROOF:
99=(3+2*6.325)*6.325
99=(3+12.65)*6.325
99=15.65*6.325
99~99