Question 979375
Along the length, the ship could carry {{{1200/30=40}}} containers.
Along the width, the ship could carry {{{300/10=30}}} containers.
Height-wise it can carry 4 containers. 
So all together,
{{{N=40*30*4}}}
{{{N=4800}}} containers
.
.
{{{2(x+2)-4x=12}}}
{{{2x+4-4x=12}}}
{{{-2x=8}}}
{{{x=-4}}}
.
.
{{{5(3z-7z)=4}}}
{{{5(-4z)=4}}}
{{{z=-4/20}}}
{{{z=-1/5}}}