If this is a system of equations then: Multiply 5x-y=3 by -2 => -10x+2y=-6 Now you sum the equations: 10x-10x+7y+2y=-3-6 => 9y=-9 Then just divide by 9: y=-1 Now to get x, choose one of the equations and use the value we got from y: 5x-(-1)=3 => 5x+1=3 => 5x=3-1 => 5x=2 => x=2/5
