Question 112309
LENGTH=W+5
AREA=L*W
75=(W+5)W
75=W^2+5W
W^2+5W-75=0
USING THE QUADRATIC EQUATION WE GET:
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}} 
W=(-5+-SQRT[5^2-4*1*-75])/2*1
W=(-5+-SQRT25+300])/2
W=(-5+-SQRT325)/2
W=(-5+-18.03)/2
W=-5+18.03
W=13.03/2
W=6.515 SOLUTION.
L=6.515+5
L=11.515 SOLUTION.
PROOF:
6.515*11.515=75
75=75