Answer:
m<3 = 60
Step-by-step explanation:
Angle 3 and the angle measuring 8x + 140 are vertical angles, so they are congruent.
m<3 = 8x + 140
Because of the parallel lines, same side interior angles are supplementary. Angle 3 and the angle measuring -6x + 60 are supplementary angles, so their measures add to 180 degrees.
m<3 + (-6x + 60) = 180
8x + 140 - 6x + 60 = 180
2x + 200 = 180
2x = -20
x = -10
m<3 = 8x + 140 = 8(-10) + 140 = -80 + 140 = 60
