PLZ HELP! QUESTIONS ARE BELOW! :D

Plz (02.03 mc) which sequence of transformations will change figure pqrs to figure p′q′r′s′? (5 points) select one: a. counterclockwise rotation about the origin by 90 degrees followed by reflection about the x-axis b. counterclockwise rotation about the origin by 90 degrees followed by reflection about the y-axis c. counterclockwise rotation about the origin by 180 degrees followed by reflection about the x-axis d. counterclockwise rotation about the origin by 180 degrees followed by reflection about the y-axis

What are “like terms”? why can we only add like terms?

It says factor each expression 49x-28?