$g(x) =\frac{3-5x}{5-x}$
I know that I am retarded for not being able to do this on my own. Algebraically you just have to solve for x. Even so, I can't do it.
$g(x) =\frac{3-5x}{5-x}$
I know that I am retarded for not being able to do this on my own. Algebraically you just have to solve for x. Even so, I can't do it.
Hint: $y=\frac{3-5x}{5-x}$ so $y(5-x)=3-5x$. Now collect terms involving $x$ on one side and those not involving $x$ on the other and solve for $x$.
Maybe you could start with a less complicated example and build up from there. Why don't you try finding the inverse function of $f(x) = x + 3$ using the idea that Timothy gave you of putting $y = x + 3$ and then solving for $x$. Then you can try $f(x) = 7x - 2$ for instance. Now you could also try $f(x) = \frac{3}{x}$ for example.
Something that is sometimes very useful is to consider "easier" problems related to your original problem and trying to solve those.
I believe the point is to gain some experience on what the particular difficulty may be, and that the "harder" problem may combine some of the difficulties that you will have treated in the particular, less complicated examples that you considered. This advice is treated by Polya in his excellent book about problem solving.