Question

Решите систему уравнений:
а.){x+2y-3z=4
y+5z=7
-z=-1

Answer 1

x+2y-3z=4         x+2y-3=4       x+2*2=4+3          x=3
y+5z=7              y+5=7            y=2                    y=2
-z=-1                  z=1                z=1                    z=1