Question 1041883
{{{system(L=w+6,A=w*L)}}}
{{{A=w(w+6)}}}
{{{A=w^2+6w}}}



{{{system(L+6,w+6,2A=(w+6)(L+6))}}}
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{{{2A=(w+6)((w+6)+6)}}}
{{{2A=(w+6)(w+12)}}}
{{{2A=w^2+18w+72}}}



{{{system(2A=2w^2+12w,2A=w^2+18w+72)}}}
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{{{highlight(2w^2+12w=w^2+18w+72)}}}
Solve this for w, the width of the original rectangle.