Question 345589
x is width
l =3x
.
V = l*w*h
{{{1125 = 3x*x*h}}} or {{{1125 = 3*x^2*h}}}
{{{h=( 375/x^2)}}}
surface Area is
2l*w + 2w*h + 2l*h 
.
substitute for h:
2*(3x^2) + 2*x*(375/x^2) + 2**3x*(375/x^2)
{{{6*x^2 + 750/x + 2250/x}}}
.
{{{6*x^2 + 3000/x}}} is the surface Area