Answer:
x = 6
y = -9
Step-by-step explanation:
Here, we want to solve the simultaneous equation using the substitution method
from the first equation;
x = -3-y
Put this in the second equation
-3-y + 2y = -12
-3 + y = -12
y = -12 + 3
y = -9
Recall;
x = -3-y
x = -3-(-9)
x = -3 + 9
x = 6
