-4x-6=? Help please its for right know

Will gve pints stars and brainliest

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

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