Question 1139273
Let {{{ h }}} = the height of the box
{{{ V = w^2*h }}}
{{{ 2 = w^2*h }}}
{{{ h = 2/w^2 }}}
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{{{ A = 2*w^2 + 4*w*h }}}
{{{ A = 2*w^2 + 4*w*( 2/w^2 ) }}}
{{{ A(w) = 2*w^2 + 8/w }}}
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{{{ C(w) = 20*( 2*w^2 ) + 30*( 8/w ) }}}
{{{ C(w) = 40w^2 + 240/w }}}