Question 881356
{{{L=W-7}}}
For a rectangle,
{{{A=L*W}}}
{{{(W-7)W=99}}}
{{{W^2-7W=99}}}
{{{W^2-7W-99=0}}}
{{{(W^2-7W+49/4)-49/25-99=0}}}
{{{(W-7/2)^2-49/4-396/4=0}}}
{{{(W-7/2)^2=445/4}}}
{{{W-7/2=0 +- sqrt(445)/2}}}
{{{W=7/2 +- sqrt(445)/2}}}
Only a positive width makes sense in this situation,
{{{W=7/2+ sqrt(445)/2}}}
Then,
{{{L=7/2+sqrt(445)/2-7}}}
{{{L=-7/2+sqrt(445)/2}}}