Question

1) 2x – 3y - z = 7

Answer 1

Answer:

x = 3

Step-by-step explanation:

2x - 3y - z = 7 (equation 1)

3x + 5y - 3z = -2 (equation 2)

4x – y + 2z = 17 (equation 3)

(1) * 3 : 6x - 9y - 3z = 21 (1)'

(1)' - (2) :  3x - 14 y = 23 (equation 4)

(1) * 2 : 4x - 6y - 2z = 14 (1)"

(1)" + (3) : 8x - 7y = 31 (equation 5)

(5)*2 : 16x - 14y = 62 (5)'

(5)' - (4) : 13x = 39

              x = 3

So thus, x = 3 in this system of equations, you can plug x back into equation 4 or 5 to find y and then plug x and y back into equations 1, 2, or 3 to find z