Solve the system by substitution. If the system is inconsistent or has dependent equations, say so.
x - 
y = -18
x + 
y = -9
A. {(0, 12)}
B. {(0, -12)}
C. {(-12, 0)}
D. {(12, 0)}
Answer: C
Mathematics
x - y = -18x + y = -9A. {(0, 12)}
B. {(0, -12)}
C. {(-12, 0)}
D. {(12, 0)}
Answer: C
