How do you find the inverse of $f(x)=(7/x)-3$ ?

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Answer 1 · 2016-02-01T05:44:14

$f^-1(x)=7/(x+3$

Given that $f(x)=7/x-3$
We know that if $f(x)=y$ then $f^-1(y)=x$

So, from the main equation, by rearranging we get
$y=7/x-3\impliesy+3=7/x\implies(y+3)/7=1/x$
$:.x=7/(y+3)$

We know what $x$ is, so now you know why the answer above is right. (Just replace $y$ to $x$ )

How do you find the inverse of f(x)=(7/x)-3f(x)=(7/x)-3?