Abicycle with 19-in.-diameter wheels has its gears set so that the chain has a 6-in. radius on the front sprocket and 3-in. radius on the rear sprocket. the cyclist pedals at 200 rpm.

hi friend

here is your answer

there are two angles that are alternate interior angle with angle 9

the angle 15 and angle 7 are alternate interior angle with angle 9.

hope it is for you so mark my answer as a brainliest

12r - 8 - 12

you have to combine like terms. below i have bolded the like terms:

12r - 8 - 12

together it combines to:

12r - 20

hope this !