Question

`x1+2x2-x3=3, 2x1+x2-2x3=1, 3x1+4x2-5x3=5`

Answer 1

Answer: x1 = 0; x2 = 5/3; x3 = 1/3

x1 + 2x2 - x3 = 3 => 2x1 + 4x2 - 2x3 = 6

2x1 + x2 - 2x3 = 1

=> 4x2 - x2 = 5

⇔ 3x2 = 5

⇔ x2 = 5/3

with x2 = 5/3, we have: x1 - x3 = 3 - 10/3 = -1/3

3x1 - 5x3 = 5 - 4.5/3 = -5/3

=> x1 = 0

x3 = 1/3

Explanation: