Identify the variation as direct, inverse, joint or combined.
xy = c

A. direct
B. inverse
C. joint
D. combined

Hector and alex traded video games. alex gave hector one fourth of his video games in exchange for 6 video games. then he sold 3 video games and gave 2 video games to his brother. alex ended up with 16 video games. how many video games did alex have when he started?

Suzanne began a trip with 18 1/2 gallons of gas in the gas tank of her car if she hughes 17 3/4 gallons on the trip how many gallons does she have left once she finish the trip

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.