I have 2 lines are parallel you can be sure that what

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

Can someone me and plz do the problem

Which is the correct first step in finding the area of the base of a cylinder with a volume of 26x cubic meters and a height of 6.5 meters? v=bh 6.5=b(26x) v=bh v=26pi+(6.5) v=bh v=26pi(6.5) v=bh 26pi=b(6.5)