Hiii please help i’ll give brainliest:)

If f(x)=3x+1 and f^-1=x-1/3, then f^-1(7)=

Suppose a gym membership has an initial enrollment fee of $75 and then a fee of $29 a month. which equation models the cost, c, of the gym membership for m months?

Ron has 8 caps and 4 of his caps are blue. thes rest of his cap are red. how many of ron's caps are red