x + 3y = 6 ; 2x – 3y = 12

To solve the system of equations:

1. Start by eliminating one variable. In this case, we can eliminate the variable "y" by adding the two equations together.

   (x + 3y) + (2x - 3y) = 6 + 12

   Simplifying, we get:

   3x = 18

2. Divide both sides of the equation by 3 to solve for "x":

   3x/3 = 18/3

   x = 6

3. Substitute the value of "x" back into one of the original equations to solve for "y". Let's use the first equation:

   6 + 3y = 6

   Subtract 6 from both sides:

   3y = 0

4. Divide both sides of the equation by 3 to solve for "y":

   3y/3 = 0/3

   y = 0

Therefore, the solution to the system of equations is x = 6 and y = 0.