Is my answer correct?

Question

Solve the system: {3x – y = 6} {xy = 24} There are two solutions:

(x₁, y₁) (x₂, y₂). Evaluate: x₁+y₁+x₂+y₂=

(A) 8

(B) 0

(C) 8 + 6√3 i

(D) -4

(E) None of these

For this I got; (D) -4. Is my answer choice correct?

Answer 1

Yes! I substitute y = 24/x into first equation, multiply that by x and rearrange, then factor yields (x+2)(x-4) = 0. The two solutions x = -2 and 4, with the corresponding y values -12 and 6, do add up to -4.