1.
Let the system of linear equations
x+y+kz=2x + y + kz = 2

2x+3y−z=12x + 3y - z = 1

3x+4y+2z=k3x + 4y + 2z = k

have infinitely many solutions. Then the system
(k+1)x+(2k−1)y=7(k+1)x + (2k-1)y = 7

(2k+1)x+(k+5)y=10(2k+1)x + (k+5)y = 10

has: