Question 708794
How high is it? h = height
x^2h=60
{{{h=60/x^2}}}


AREA OF SIDES
{{{4(hx)}}}={{{4(60/x^2)x}}}={{{60/x}}}

AREA OF BOTTOM
{{{x^2}}}

AREA OF TOP
{{{x^2}}}


COST OF THE BOX = f(x)
Uses the given prices.
{{{f(x)=40*x^2+10*60/x+30*x^2}}}
Simplification, {{{highlight(f(x)=40x^2+600/x+30x^2)}}}