Question

Resolva o sistema escalonado {2x - y + z = 3
3y + 5z = 55
4z = 20

Answer 1

x=4,y=10 e z=5... espero estar certo.

Answer 2

....2x - y + z = 3
...........3y + 5z = 55
................... 4z = 20

z=20/4
z=5


3y + 5z = 55
3y+5(5)=55
3y+25=55
3y=55-25
y=30/3
y=10



2x - y + z = 3
2x-10+5=3
2x=3+10-5
2x=8
x=8/2
x=4

Resposta: x=4;y=10;z=5