Vira um sistema:

2x - 3x + 3y - y + 2z + z = 2 + 2 + 1

-1x = 5 - 2y - 3z

x = ( 5 - 2y - 3z) / -1

x = -5 + 2y +3z

Ola Michael

2x - y = 2 (I)

3y + z = 2 (II)

-2x + 2z = 1 (III)

(I) + (III)

2z - y = 3

z + 3y = 2 (II)

2z + 6y = 4

2z - y = 3

7y = 1

y = 1/7

2z - 1/7 = 21/7

2z = 22/7

z = 11/7

2x - y = 2

2x - 1/7 = 14/7

2x = 15/7

x = 15/14

resumindo

x = 15/14

y = 1/7

z = 11/7

pronto