Question 257174

1.{{{3x + y = 1}}}
2.{{{x-2y = 5}}}
Multiply eq.l 1 by 2 and add to eq. 2,
{{{6x+2y+x-2y=2+5}}}
{{{7x=7}}}
{{{x=1}}}
Now use either eq. 1 or eq. 2 to solve for y,
{{{3x+y=1}}}
{{{3+y=1}}}
{{{y=-2}}}