What divide by what equals 21

Aball is dropped from a height of 10m above the ground. it bounce to 90% of its previous height on each bounce. what is the approximate height that the ball bounce to the fourth bounce?

60 2(x + 2) in the diagram, gef and hef are congruent. what is the value of x?

The equation |pl = 2 represents the total number of points that can be earned or lost during one turn of a game. which best describes how many points can be earned or lost during one turn? o o -2 2 oor 2 -2 or 2 o