Answer:
C. (-3,6)
Explanation:
Take 10x + 7y = 12 as first equation and 8x + 7y = 18 as second equation.
Subtracting both equations, you will get
10x + 7y - 8x - 7y = 12 - 18
2x = -6
x = -3
Substitute value of 'x' in any of the given equation :-
10x + 7y = 12
10 * -3 + 7y = 12
7y = 12 + 30
y = 42/7
y = 6