$$T(n)=5T(\frac{n}{2})+n\log n$$ $$T(n)=9T(\frac{n}{3})+n^2$$ $$T(n)=2T(\frac{2n}{3})+n^{1.5}$$
What are the running times of each $T(n)$? Each one looks like the form of the Master Theorem, but only the second one actually applies. For example, if we take the first $T(n)$: $T(n)=5T(\frac{n}{2})+n\log n$ so $a = 5, b = 2, c = 1,$ and $k=1$, but $c \not = \log_2 5$, so we can't use the master theorem here. Similarly for the third recurrence. For the second recurrence I found that $T(n)=\Theta(n^2)$, but I need methods to quickly solve the other two in an exam-type setting.