Answer:
(x, y, z) = (7, 9, 90)
Step-by-step explanation:
The two acute angles between l1 and l2 are vertical, so congruent.
(9x -7) = 8x
x = 7 . . . . . . . . . add 7-8x
These are supplementary to the obtuse angle between those lines:
8(7) + (13y +7) = 180
13y = 117 . . . . subtract 63
y = 9 . . . . . . . divide by 13
The angle marked z is supplementary to the angle marked as a right angle.
z + 90 = 180
z = 90
