Solving systems by Multiplying.

4x-2y=7
3x+6y=9

Multiply Eq1 by 3 and add:

12x-6y = 21
3x+6y = 9
Sum:15x = 30
X = 2

In Eq2, replace x with 2:
3*2 + 6y = 9
6 + 6y = 9
6y = 9 - 6 = 3
Y = 1/2.