Question 1045783
x for length
y for width
p for perimeter, given


{{{x=y+6}}}
-
{{{2x+2y=p}}}
{{{2(y+6)+2y=p}}}
{{{2y+12+2y=p}}}
{{{4y+12=p}}}
{{{4y=p-12}}}
{{{highlight(y=(p-12)/4)}}}



You do the rest.