The function f is defined as y=f(x)= (2x+1)/(x-3), where x does not equal 3. Find the value k so that...

The function f is defined as y=f(x)= (2x+1)/(x-3), where x does not equal 3. Find the value k so that f^-1 (x) = (3x+1)/(x-k)
a) 0
b) 1
c)2
d)-1
e) -2

I don't understand what the question is asking for (what the second sentence has to do with the first, what the inverse equation is referring to). So any help on that and/or the steps for getting the answer would be much, much appreciated. Thanks!

y = (2x + 1)/(x - 3)

yx - 3y = 2x + 1

yx - 2x = 3y + 1

x = (3y + 1)/(y - 2)

y = (3x + 1)/(x - 2) = f^-1(x)

k = 2

To get the inverse switch x and y and solve for y.
x = (2y+1)/(y-3)
xy-3x = 2y+1
y(x-2) = (3x+1)
y = (3x+1)/(x-2)
k=2
Answer c)

y = (2*x + 1)/(x - 3)

x = (2*y + 1)/(y - 3)

x*y - 3*x = 2*y + 1

x*y - 2*y = 3*x + 1

y*(x - 2) = 3*x + 1

f^-1(x) = y = (3*x + 1)/(x - 2), so k = 2, c

hmm