[tex]\huge{\boxed{pq^9}}[/tex]
An exponent is multiplying the same thing by itself a number of times.
For example, [tex]10^2\ =\ 10*10\ =\ 100[/tex]
There is one [tex]p[/tex]. [tex]p^1[/tex]
There are nine [tex]q[/tex]s. [tex]q^9[/tex]
This leaves us with [tex]p^1 * q^9[/tex], or [tex]p^1 q^9[/tex].
We don't need a power of one, so we can just keep [tex]p*q^9[/tex], or [tex]\boxed{pq^9}[/tex]