Question 930348
From eq. 2,
{{{y=-2x+30}}}
Substitute into eq. 1,
{{{5x+3(-2x+30)=80}}}
{{{5x-6x+90=80}}}
{{{-x=-10}}}
{{{x=10}}}
Then,
{{{y=-2(10)+30}}}
{{{y=-20+30}}}
{{{y=10}}}