college alg
posted by ALLI on .
the function f(x)=6x+9/3x7
find the inverse and check answer
f^1(x)=?
please show work

I have a strong feeling you meant
f(x) = (6x+9)/(3x7)
if so, let
y = (6x+9)/(3x7)
inverse:
x = (6y+9)/(3y7)
solving that for y ....
3xy  7x = 6y+9
3xy  6y = 7x+9
y(3x  6) = 7x+9
y = (7x+9)/(3x6)
f^1 (x) = (7x+9)/(3x6)
check:
f(0) = 9/7
f^1(9/7) = (7(9/7) + 9)/(3(9/7)6)
= 0/...
= 0
(This does not prove that my answer is correct, but shows a very strong probability that it is correct)