The angles (4x+6)° and (6x-16)° are alternate interior angles, then they are congruent.
4x + 6 = 6x - 16
6 + 16 = 6x - 4x
22 = 2x
22/2 = x
11 = x
In consequence, the (6x-16)° measures:
6(11) - 16 = 66 - 16 = 50°
This angle and the angle (y+9)° are vertical angles, then they are congruent.
y + 9 = 50
y = 50 - 9
y = 41
