Minus 2x+y=8 from 3x+y=11 so that the y's cancel out (y-y=0).
Then we get the equation 3x-2x=11-8.So we get x=3.We can substitute this value back into one the orginal equations: y=11-3(3)=2 - so y=2.We can check these values are correct by substituting them into the other equation: 2(3)+2=8.Hence our solutions are correct.