Integrate rational functions Please show all steps

a$){\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{x-2}{x^{2}3x}dx$

b$){\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{x^2-x}{(x1)(x^{2}1)}dx$

Trigonometric substitution

a$){\displaystyle \underset{0}{\overset{1}{}}}\frac{x^3}{\sqrt[\phantom{2}]{4-x^2}}dx$

b$){\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\sqrt[\phantom{2}]{3-2x-x^2}dx$