Question 200555
Start with the formula for the area of a rectangle:
{{{A = L*W}}} Substitute: {{{A = x^2+50x}}} and {{{W = x}}}
{{{x^2+50x = L*x}}} Divide both sides by x.
{{{(x^2+50x)/x = L}}} Simplify.
{{{highlight(L = x+50)}}}