In this system of equations, I'll do elimination. Ok, so what we are trying to do is to eliminate a variable, but we can't. So since -2y is negative, and y has a coefficient of 1 and is positive, let's multiply the first whole equation by 2.
2 times (3x+y=11) is 6x+2y=22. (I just used distributive property.) Now let's add from left to right.
6x plus x is 7x, 2y plus -2y is 0, and 22 plus 6 is 28. Now we have this simple equation, 7x=28. We can simply divide each side by 7, to get x as 4. So x=4 in this set of equations. Now all we need to do is plug x in the equation then solve for y. For this system of equations, I'll use the first equation, because it is easier. So I'll plug x as 4 into the equation to get 12+y=11. Now we can simply solve for y. 11-12 is -1, so y must equal -1. So y=-1. Therefore, x=4 and y=-1. Hope I helped.

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