How to rename the fraction part of the problem

Factor and solve to find roots x squared -x - 90 =0

For a function f(x), a) if f(7) = 22 then f^-1(22) = b) f^-1(f(c)) =

Adolphin is swimming with her friend. the dolphin jumps to a height of 4.54.54, point, 5 meters above the surface of the water as her friend swims 9.89.89, point, 8 meters directly below her. what is the position of the dolphin's friend relative to the surface of the water? meters