Question 1027868
w and L for width and length;


{{{system(L=w+10,wL=A,andThenNewDimensions,L+10=w+10+10,w+10)}}}


New area,
becomes the old area multiplied by 3:
{{{(L+10)(w+10)=3A}}}
{{{wL+10w+10L+100=3wL}}}
{{{-2wL+10w+10L+100=0}}}
{{{wL-5w-5L-20=0}}}
{{{w(w+10)-5w-5(w+10)-20=0}}}-----substituted for L
{{{w^2+10w-5w-5w-50-20=0}}}
{{{w^2+0-70=0}}}
{{{w^2=70}}}
{{{highlight(w=sqrt(70))}}}
-
{{{highlight(L=10+sqrt(70))}}}