Đề bài

Thực hiện các phép tính sau:

a) $\dfrac{{8y}}{{3{x^2}}} \cdot \dfrac{{9{x^2}}}{{4{y^2}}}$

b) $\dfrac{{3x + {x^2}}}{{{x^2} + x + 1}} \cdot \dfrac{{3{x^3} - 3}}{{x + 3}}$

c) $\dfrac{{2{x^2} + 4}}{{x - 3}} \cdot \dfrac{{3x + 1}}{{x - 1}}:\dfrac{{{x^2} + 2}}{{6 - 2x}}$

d) $\dfrac{{2{x^2}}}{{3{y^3}}}:\left( { - \dfrac{{4{x^3}}}{{21{y^2}}}} \right)$

e) $\dfrac{{2x + 10}}{{{x^3} - 64}}:\dfrac{{{{\left( {x + 5} \right)}^2}}}{{2x - 8}}$

f) $\dfrac{1}{{x + y}}\left( {\dfrac{{x + y}}{{xy}} - x - y} \right) - \dfrac{1}{{{x^2}}}:\dfrac{y}{x}$