Система уравнений {6(x+y)-y=-1, 7(y+4)-(y+2)=0

Question

Система уравнений {6(x+y)-y=-1, 7(y+4)-(y+2)=0

Answer 1

6x+6y-y=-1
7y+4y-y-2=0
6x+5y=-1
10y=2
y=1/5
6x+5*1/5=-1
6x+1=-1
6x=-2
x=-1/3