Question

x+y+z=1 2x-3y+2z=2 4x+9y+4z=4​

Answer 1

{x+y+z=1
{2x-3y+2z=2
{4x+9y+4z=4

[1 1 1 | 1]
[2 -3 2| 2]
[4 9 4 | 4]

[1 1 1 | 1]
[0 -5 0| 0]
[0 5 0 | 0]

[1 1 1 | 1]
[0 1 0 | 0]
[0 0 0| 0]

[1 1 1 | 1]
[0 1 0 | 0]

[1 0 1 | 1]
[0 1 0| 0]

X+z=1
Y=0

(X,y,z)=(1-z,0,z)