21 Answer:
[tex] \frac{3}{a} [/tex]
22 Answer:
[tex] \frac{1}{ {b}^{3} } [/tex]
23 Answer:
[tex] \frac{ {4a}^{2}c^{3} }{ {b}^{2} } [/tex]
24 Answer:
[tex]9c ^{4} [/tex]
25 Answer:
[tex] - \frac{1}{ {a}^{2} } [/tex]
26 Answer:
[tex] \frac{1}{ {c}^{2} } [/tex]
