Question

Calcule o determinante do sistema.

Answer 1

{x+y+2z=9
{x+2y+z=8
{2x+y+z=7
∆=[1. 1. 2]. 1. 1
[1. 2. 1]. 1. 2
[2. 1. 1]. 2. 1
∆=2+2+2-8-1-1
∆=6-10
∆=-4
[9. 1. 2]. 9. 1
[8. 2. 1]. 8. 2
[7. 1. 1]. 7. 1
∆x=18+7+16-28-9-8
∆x=41-45
∆x=-4
[1. 9. 2]. 1. 9
[1. 8. 1]. 1. 8
[2. 7. 1]. 2. 7
∆y=8+18+14-32-7-9
∆y=40-48
∆y=-8
[1. 1. 9]. 1. 1
[1. 2. 8]. 1. 2
[2. 1. 7]. 2. 1
∆z=14+16+9-36-8-7
∆z=39-51
∆z=-12
∆x/∆=-4/-4=1br />∆y/∆=-8/-4=2
∆z/∆=-12/-4=3