Question 1075865
Total area combined, minus the pool upper surface area, is the area of just the border around the pool.
{{{highlight_green((37+2w)(47+2w)-37*47=352)}}}



{{{2*47w+2*37w+4w^2=352}}}

{{{4w^2+2(47+37)w-352=0}}}

{{{4w^2+2*84w-352=0}}}

{{{w^2+42w-88=0}}}


discriminant,  {{{42^2-4*(-88)=2116=46^2}}}


{{{w=(-42+46)/2}}}


{{{highlight(w=2)}}}