Question 1119317
{{{system(x+y+z=290,11x+7y+2z=1750,15x+8y+3z=2280)}}}


{{{system(12x+8y+3z=2040,15x+8y+3z=2280)}}}

{{{-3x=-240}}}

{{{highlight(x=80)}}}

{{{system(y+z=210,7y+2z=870)}}}


{{{system(2y+2z=420,7y+2z=870)}}}

{{{-5y=-450}}}

{{{highlight(y=90)}}}

{{{2z=240}}}

{{{highlight(z=120)}}}