Question 893526
w and L for width and  length, in that order.


L=-5+4w and 2w+2L=30+6w.  These are just the symbolism translations of the description.


The perimeter description equation simplifies to{{{w+L=15+3w}}},
{{{L=15+2w}}}
{{{2w-L=-15}}}
{{{L-2w=15}}}


Substituting for L,
{{{(4w-5)-2w=15}}}
{{{2w-5=15}}}
{{{2w=20}}}
{{{highlight(w=10)}}}
-
Now find L.
{{{L=4w-5}}}
{{{L=4*20-5}}}
{{{highlight(L=75)}}}


Area is wL.