Nine less than twelve in an algebraic expression

In the figure shown below, m < 40 and ab =8. which equation could be used to find x?

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?

True or false: the graph of y=f(bx) is a horizontal compression of the graph y=f(x) if b< 1