Question 27159
{{{5x+10y=30}}}
{{{5x+3y=2}}} At this point you need to subtract one equation from the other, not add them. When you do that you get:
{{{7y=28}}}
{{{y=4}}}

Substituting in for the first equation:
{{{x+2y=6}}}
{{{x+2y=6}}}
{{{x+2(4)=6}}}
{{{x=-2}}}