I would say B. By multiplying the first equation by -5, you create -5y. If you add that to the second equation, your cancelling out the 5y term, and get a new equation with only z and a constant.
Answer:
Step-by-step explanation:
2x + 5 = -x - 1
3x + 5 = -1
3x = -6
x = -2
y = 2 - 1
y = 1
(-2, 1)
5,180,000,000
I hope this helps.
I think the answer is 14.