Đề bài

Thực hiện phép tính:

a) $\dfrac{{5{\rm{x}} - 4}}{9} + \dfrac{{4{\rm{x}} + 4}}{9}$          

b) $\dfrac{{{x^2}y - 6}}{{2{{\rm{x}}^2}y}} + \dfrac{{6 - x{y^2}}}{{2{{\rm{x}}^2}y}}$

c) $\dfrac{{x + 1}}{{{x^2} - 5{\rm{x}}}} + \dfrac{{x - 18}}{{{x^2} - 5{\rm{x}}}} + \dfrac{{x + 2}}{{{x^2} - 5{\rm{x}}}}$                          

d) $\dfrac{{7y}}{3} - \dfrac{{7y - 5}}{3}$

e) $\dfrac{{4{\rm{x}} - 1}}{{3{\rm{x}}{y^2}}} - \dfrac{{7{\rm{x}} - 1}}{{3{\rm{x}}{y^2}}}$                                                

g) $\dfrac{{3y - 2{\rm{x}}}}{{x - 2y}} - \dfrac{{x - y}}{{2y - x}}$