Question 747042
{{{
P=2(l+w)
}}}



becomes

{{{
54=2(l+w)
}}}



or


{{{
l=27-w
}}}

and
{{{
A=lw
}}}



becomes

{{{
lw=140
}}}


then

{{{
(27-w)w=140
}}}


expanding and rewriting...


{{{
w^2-27w+140=0
}}}


and the equation factors to

{{{
(w-20)(w-7)=0
}}}



This means that w=20 and l=7