2more than 5 minus -4, write the expression

Which letters from the table represent like terms? a and b b and c a and d b and d

The radius of the earth is two times the radius of the moon. what fraction of the volume of the earth is the volume of the moon?

Me with this assignment ! i only partially understand, so explain. also it's a work sample. at the championship bike race, steve and paula were fighting for first place. steve was 175 feet ahead of paula and had only 300 feet left to go. he was very tired and was going only 9 feet per second. paula was desperate to catch up and was going 15 feet per second. who won the bike race and by how far did she/he win?