Respostas

  • Usuário do Brainly
2013-07-29T05:31:22-03:00
X - 2y - 2z = -1 .... (i)
x - 2z = 3 ............ (ii)
y - z = 1 ............. (iii)

De (ii) → x = 2z + 3
De (iii) → y = z +1 

x - 2y - 2z = (2z+3) - 2(z+1) - 2z = 2z + 3 - 2z - 2 - 2z = 1 - 2z 

1 - 2z = -1 
1 + 1 = 2z
2z = 2
z = 2/2 
z = 1

x = 2z + 3 = 2.1 + 3 = 2 + 3 = 5
y = z + 1 = 1 + 1 = 2
z = 1

Logo:

x = 5, y = 2 e z = 1.
3 4 3