Can someone show me step by step for this system of equations? (number 5)

x = 3, y = -1, z = -4

Step-by-step explanation:

2x + y - z = 9 (1)

- x + 6y + 2z = -17 (2)

5x + 7y + z = 4 (3)

(3) + (1)

7x + 8y = 13 (4)

2 × (1)

4x + 2y - 2z = 18 (5)

(5) + (2)

3x + 8y = 1 (6)

(4) - (6)

4x =12

x = 3

substitute x = 3 in (6)

9 + 8y = 1

8y = -8

y = -1

substitute x = 3 and y = -1 in (1)

2 × 3 + (-1) - z = 9

6 - 1 - z = 9

5 - z = 9

z = 5 - 9

z = -4

c. t= 4 hours

Step-by-step explanation:

this is the only answer which only states the time.