Simplifying
2x + -1y = 9
Solving
2x + -1y = 9
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add 'y' to each side of the equation.
2x + -1y + y = 9 + y
Combine like terms: -1y + y = 0
2x + 0 = 9 + y
2x = 9 + y
Divide each side by '2'.
x = 4.5 + 0.5y
Simplifying
x = 4.5 + 0.5y
Hope this helps :)
~I tried to space it out so it wont look like a bunch of mess scrambled up xD~