Answer:
the solution is (6, 3)
Explanation:
Subtract the second equation from the first, as indicated:
3x+6y=36
-( 3x-6y=0)
-----------------
12y = 36. Then y = 36/12 = 3.
Subbing 3 for y in the second equation, we get 3x - 6(3) = 0, or 3x = 18, or x = 6.
Thus, the solution is (6, 3).