6 x plus 9 y equals 18?

Answer 1

The given equation can be simplified to 2x + 3y = 6 but that is about it.

Given 2 unknown variables (x and y) you need two independent equations to solve for them. The only other thing you can so with the above equation is to express

y in terms of x : y = (6 - 2x)/3 = 2 - 2x/3

or

x in terms of y: x = (6 - 3y)/2 = 3 - 3y/2

Both different (and possibly clumsier) ways of saying the same thing as the original equation.