Solve the System by Substitution $x+y=-1$ $x+y=-6$ A) $\{(0,-7)\}$ B) $\varnothing$ ; Inconsistent System
C)

Multiple Choice

Solve the system by substitution. If the system is inconsistent or has dependent equations, say so.
- $x+y=-1$
$x+y=-6$

A) $\{(0,-7) \}$
B) $\varnothing$ ; inconsistent system
C) $\{(-1,-6) \}$
D) $\{(x, y) \mid x+y=-6\}$ ; dependent equations