Well, you have one equation, or rather an inequality. There are two variables x and y, so with only one equation you can't solve it. No-one can. But you can write something that links the two variables. Take 11x from each side: y>18-11x. You can now work out y for different values of x. If, for example, x=0, y>18 (y is bigger than 18). If x=1, y>7, and so on. You can also draw a graph of y=18-11x, which is a straight line. The whole area above the line represents y>18-11x.