You see how these 2 angles marked are both inside the 2 parallel lines?
And they are on opposite side of the transversal, the line crossing the 2 parallel lines?
These 2 angles are alternate interior angles and they are equal, I think you can do the last part by yourself.
I think its B Because u have the total of pencils and how much they cost now u need to how know many pins you have to know how many they have in total
Answer:
D answer to dis question is 21