Answer:
C. (-4,10,7)
Explanation:
Use the first equation to substitute for y in the last equation:
x = (x +2z) -14
14 = 2z . . . . . . add 14-x
7 = z . . . . . . . . divide by 2
Now, find x:
7 = -1 -2x . . . . substitute for z in the second equation
8/-2 = x = -4 . . . . . add 1, divide by -2
Finally, find y:
y = -4 +2(7) = 10 . . . . . substitute for x and z in the first equation
The solution is (x, y, z) = (-4, 10, 7).