Question

Plz help

x+2y+z=9

x+y-z=5

3x-y+2z=12

solve for x, y, and z

solve with substitution

Answer 1

`x2y + z = 9 \\ \\ 1. \: x + 2y + z + - 2y = 9 + - 2y \\ x + z = - 2y + 9 \\ 2. \: x + z + - z = - 2y + 9 + - z \\ x = - 2y - z + 9 \\ \\ \\ x + y - z = 5 \\ \\ 1. \: x + y - z + - y = 5 + - y \\ x - z = - y + 5 \\ 2. \: x - z + z = - y + 5 + z \\ x = - y + z + 5 \\ \\ \\ 3x - y + 2z = 12 \\ 1. \: 3x - y + 2z + y = 12 + y \\ 3x + 2z = y + 12 \\ 2. \: 3x = y - 2z + 12 \\ 3. \: (3x)/(3) = (y - 2z + 12)/(3) \\ x = (1)/(3) y + ( - 2)/(3) z + 4`