Question

4x + 2y = 12
x – y = 3

Answer 1

No solutions.

Answer 2

Solve the second equation for x:
x = 3 + y

Substitute this x in for the x in the first equation:
4(3 + y) + 2y = 12
12 + 4y + 2y = 12
6y = 0
y = 0

Plug this y back into the second equation you solved for x:
x = 3 + y
x = 3 + (0)
x = 3

So, y = 0, x = 3.