Answer:
(x^(-5/7))/2
Step-by-step explanation:
To get the inverse function you switch x and y (y is the same as f(x))
so we start with y=(2x)^-7/5
and switch x and y, so
x=(2y)^-7/5
all these answers are in terms of x, so isolate y by..
taking the -(5/7)ths power of both sides
x^(-5/7)=2y
and then dividing by 2 on both sides
(x^(-5/7))/2=y
again, y is the same as the the inverse function f^-1(x), so it's the bottom left option.