How do you solve x-y=11
2x+y=19

you take the x and y and take and add numbers till u get the correct numbers. the answer would be x=16 y=5

Actually, you put x-y=11 into slope intercept form and insert it into the other equation because y now equals x-11. then you solve for x and put it back into the equation to get y. 
x=10 and y=-1. put them back in the equations if you are unsure