Do the same sort of thing you would do to solve something like 2x + 3y = 6 for y, which I presume you have done. In that case, you treat x as if it were just a number, and isolate y on one side (some people call this "making y the subject"). You don't need to know the value of x to find an expression for y. In this example, you would subtract 2x from both sides, then divide by 3, yielding y = (6 - 2x)/3. In your problem, all you need is one division.

As for using x for multiplication, I thought someone had mentioned to you the link in our submission guidelines telling how to type math: "

Formatting Math as Text". Maybe it was someone else. Anyway, now you know.