Need help pls due in a couple of minutes

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

Find the 6th term of the expansion of (2p - 3q)11. a. -7,185,024p4q7 c. -7,185p4q7 b. -7,185,024p6q5 d. -7,185p6q5 select the best answer from the choices provided a b c d

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827