Answer:
A: (x = 34, y = -27, z = -1)
Step-by-step explanation:
Plug the variables in. It might be tedious, but it guarantees you get it right.
Let's try A first. 2(34) + 2(-27) + 6(-1) = 8. Is this correct? Yes. However, you gotta plug it in for the other three equations. 5(34) + 6(-27) + 5(-1) = 3. Is this correct? Yes again. One last equation. 5(34) + 6(-27) + 3(-1) = 5. That's correct as well. The answer is A.
In case you still weren't sure if the answer was A or not;
B: 2(33) + 2(-26) + 6(0) = 14. Right away we can see that B will be incorrect.
C: 2(35) + 2(-28) + 6(-2) = 2. Again, incorrect.
D: 2(36) + 2(-29) + 6(1) = 20. Incorrect!
A is the correct answer.
