Answer:
13
Step-by-step explanation:
Angles ( 12x - 29 ) and ( 4x + 1 ) are co - interior angles.
Sum of co - interior angles is supplementary.
12x - 29 + 4x + 1 = 180
12x + 4x - 29 + 1 = 180
16x - 28 = 180
16x = 180 + 28
16x = 208
x = 208 / 16
x = 13
