Answer:
138
Step-by-step explanation:
G + H = 180 {G, H are linear pair}
12x + 6 + 4x - 2 = 180
12x + 4x + 6 - 2 = 180
16x + 4 = 180
16x = 180 - 4
16x = 176
x = 176/16
x = 11
G = 12x + 6
= 12*11 + 6
= 132 + 6
= 138