You've already completed the first step by lining up terms with the same variables. Like addition, simply add them together column by column. x+(-x) equals 0 so it is cancelled out. 4y plus 6y is 10y. 9+11=20. We are left with 10y equals 20, so y equals 2. Then plug in the y value into either equation. I will use the first so x +4(2)=9. x must equal 1. Double check by plugging in both x and y into the second equation.