Question

Решите систему уравнений: х+у=7 у+z= -1 z+х=-2

Answer 1

1)
x+y=7
x=7-y
2)
y+z=-1
y=-1-z
3)
z+x=-2
z=-2-x
z=-2-7+y
z=-9-1-z
2z=-10
z=-5;
2)
y=-1-z
y=-1+5
y=4;
1)
x=7-y
x=7-4
x=3;