Com es resol el sistema lineal següent ?: 3x + 4y = -2, 3x + y = -20?

`3x + 4y = -2 ……………… (i)`

`3x + y = -20 ……………. (ii)`

Restant (ii) de (i) obtenim

`3y = 18`

`implies y = 6`

Posa `y = 6` in `(i)`

`implies 3x + 4 (6) = - 2`

`implies 3x + 24 = -2`

`implies 3x = -26`

`implies x = -26 / 3`