Question

2x1-x2 + 2x3= 8,
X1+x2 + 2x3= 11,
4x1+ x2+4x3=22

Answer 1

2x1-x2+2×3=8

-x+6=8

-x=-14

x1+x2+2x3=11

4x6=11

4x=2

x=0,5

4x1+x2+4x3=22

9x6=22

9x=3,6

x=0,4