Find the solution of this system of equations. separate the x- and y-values with a comma. x - 2y = 9 and x - y = 11

We can solve the equation system using elimination and subtitution method.
First, eliminate x to find the value of y
x - 2y = 9
x -   y = 11
- (substract)
     -y = -2
      y = 2
The value of y is 2

Second, subtitute 2 as y in one of the equation
x - y = 11
x - 2 = 11
x = 11 + 2
x = 13

The solution
x, y = 13, 2