First solve one of the two equations (whichever is easier) for either x or y, whichever variable is easier. Let's say you solved for x. Then plug what x equals into the 2nd equation as x. So if you got x = 2y + 1, plug that into your other equation and solve for y (you should get a number value).
Now take whatever y equals and plug that back into what you got when you solved for x (the x = 2y + 1) to get what x equals.