For This I Got 15...

Question

Solve for x, y, z: {4x–y=4} {y–5z=–12} {5x+z=19} Then evaluate: x+y+z=

(A) (161)/(3)

(B) -43

(C) 15

(D) 57

(E) None of these

For this I got, (C) 15. Is my answer correct?

Answer 1

Yes, you are correct. I got the same result as William W., using Cramer's rule. Note that you can always test your answers by substituting your values of x, y, and z back into the original 3 equations, and see if the left hand and right hand sides give the same value.

Answer 2

Yes, you are correct (x = 3, y = 8, z = 4)