sistem persamaan linear 2 variabel metode eliminasi

Yg a
4x + 2y = 18
2x - 2y = 6
------------------- +
6x = 24
x = 4

2x - 2y = 6
2 (4) - 2y = 6
8 - 2y = 6
-2y = -2
y = 1

Yg b
4p + 2a = 12
2p - 2a = 12
------------------- +
6p = 24
p = 4

2p - 2a = 12
2 (4) - 2a = 12
8 - 2a = 12
-2a = 4
a = -2