Question 172398
ok so the we have Width W and Length L=3W....we also know that area=LW
:
3W(W)=75
:
{{{3W^2=75}}}
:
{{{3W^2-75=0}}}this would be easy enough to solve without the quadratic formula but since you asked for it
:
{{{system(W=5,W=-5)}}}
since we know we cant have negative lengths
{{{highlight(W=5)}}} so 
{{{highlight(L=3(5))}}}=15
:
checking {{{3(5)^2=75}}}={{{3(25)=75}}}..and {{{75=75}}}
:
*[invoke quadratic "W", 3, 0, -75]


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