Please help me someone

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

Mis the midpoint of rq if rm equals 2x + 5 and mq equals 4x - 9 what is the length of rq

One astronomical unit (1 au) is about 1.496 alt tag missing. kilometers. if you wrote this number of kilometers in regular decimal notation (for example, 528 and 3,459 are written in regular decimal notation), how many zeros would your number have?