Which expression is equivalent to x^4-y^2 ?

What is the greater volume 72 quarts or 23 gallons

The measure of an angle is 117°. what is the measure of a supplementary angle?

The number of 8th graders who responded to a poll of 6th grade and 8 th graders was one fourtg of the number of 6th graders whi responded if a total of 100 students responddd to the poll how many of the students responded were 6 th graders