Thực hiện các phép tính sau:
a) \(\dfrac{{2{x^2} - 1}}{{x - 2}} + \dfrac{{ - {x^2} - 3}}{{x - 2}}\)
b) \(\dfrac{x}{{x + y}} + \dfrac{y}{{x - y}}\)
c) \(\dfrac{1}{{x - 1}} - \dfrac{2}{{{x^2} - 1}}\)
d) \(\dfrac{{x + 2}}{{{x^2} + xy}} - \dfrac{{y - 2}}{{xy + {y^2}}}\)
e) \(\dfrac{1}{{2{x^2} - 3x}} - \dfrac{1}{{4{x^2} - 9}}\)
g) \(\dfrac{{2x}}{{9 - {x^2}}} + \dfrac{1}{{x - 3}} - \dfrac{1}{{x + 3}}\)