Question

For the function f(x)=x+9/7-4x find f^-1(x)

Answer 1

Explanation:

`f(x)=(x+9)/(7-4x) \\put ~f(x)=y\\flip~x~and~y\\f(y)=x\\y=f^(-1)(x)\\y=(x+9)/(7-4x) \\flip~x~and~y\\x=(y+9)/(7-4y) \\x(7-4y)=y+9\\7x-4xy=y+9\\-4xy-y=9-7x\\or\\4xy+y=7x-9\\y(4x+1)=7x-9\\y=(7x-9)/(4x+1) \\or~f^(-1)(x)=(7x-9)/(4x+1)`