I don't know how to rearrange some types of formula on my homework.
The question I can't understand how to rearrange is making $x$ the subject in $y=(x+2)/(x-2)$.
Also, it asks my why $r$ cannot be made the subject in $V=\frac{2}{3}\pi r^3 + \pi r^2 h$. I can also not make $\pi$ the subject, which it asks me to do in part b. The third part asks if $r$ can be made the subject if $h$ equal to $r$, and to do so if it can.
I do not know how to do any of these.
Regarding your first question:
$y=\frac{x+2}{x-2}\Leftrightarrow y(x-2)=x+2\Leftrightarrow xy-2y=x+2$.
This should help you solve the equation for $x$.
Second question:
$r$ can be made the subject of the equation, but not without further formulas.
Third question:
If you replace $h$ with $r$, you get:
$V=\frac{2}{3}\pi r^3+\pi r^3=\frac{5}{3}\pi r^3$
Using cube roots, you can solve this equation for $r$ easily.