4.9. а) \(\frac{4m-5}{3m^2}-\frac{m+2}{m^2}\); б) \(\frac{7p+1}{3p}+\frac{2p-3}{9p}\); в) \(\frac{3z-8}{5z^2}+\frac{z-1}{z^2}\); г) \(\frac{8-9t}{22t}-\frac{t+4}{11t}\).

1. а) \(\frac{4m-5}{3m^2}-\frac{m+2}{m^2}=\frac{4m-5}{3m^2}-\frac{3m+6}{3m^2}=\frac{-m-11}{3m^2}\).
2. б) \(\frac{7p+1}{3p}+\frac{2p-3}{9p}=\frac{21p+3}{9p}+\frac{2p-3}{9p}=\frac{23p}{9p}=\frac{23}{9}\).
3. в) \(\frac{3z-8}{5z^2}+\frac{z-1}{z^2}=\frac{3z-8}{5z^2}+\frac{5z-5}{5z^2}=\frac{8z-13}{5z^2}\).
4. г) \(\frac{8-9t}{22t}-\frac{t+4}{11t}=\frac{8-9t}{22t}-\frac{2t+8}{22t}=\frac{-11t}{22t}=-\frac12\).

В знаменателях исходных дробей переменные не равны нулю.