Solve the system by back substitution.
- 4x - 8y - 22 - 6w = 4 (I)
y +62 + 2w = 8 (II)
Z + W = 2 (III)
5w = 15 (IV)
We'll start by equation (IV):
5w=15
w=3
Now, (III):
z+w=2
z+3=2
z=-1
Now, we follow to (II)
y+62+2w=8
y+62+6=8
y=8-68
y=-60
FInally, equation (I):
-4x-8*(-60)-22-6*3=4
-4x +480-22-18=4
-4x=4-440
-4x=-436
x=109
The solution set is: S={109, -60, -1, 3}
