Giải thích các bước giải:
Ta có:
\(\begin{array}{l}
\frac{{3 - 5{x^2} + 2x + {x^3}}}{{x + 3}}\\
= \frac{{{x^3} - 5{x^2} + 2x + 3}}{{x + 3}}\\
= \frac{{\left( {{x^3} + 3{x^2}} \right) - \left( {8{x^2} + 24x} \right) + \left( {26x + 78} \right) - 75}}{{x + 3}}\\
= \frac{{{x^2}\left( {x + 3} \right) - 8x\left( {x + 3} \right) + 26\left( {x + 3} \right) - 75}}{{x + 3}}\\
= \frac{{\left( {x + 3} \right)\left( {{x^2} - 8x + 26} \right) - 75}}{{x + 3}}\\
= \left( {{x^2} - 8x + 26} \right) - \frac{{75}}{{x + 3}}
\end{array}\)
