Tính: (1/2x^4 - 1/4x^3 + x):(-1/8x) =

\(\left( {\frac{1}{2}{{\rm{x}}^4} - \frac{1}{4}{{\rm{x}}^3} + {\rm{x}}} \right):\left( {\frac{{ - 1}}{8}{\rm{x}}} \right)\) = \(\frac{1}{2}\)x⁴ : \(\left( {\frac{{ - 1}}{8}{\rm{x}}} \right)\) – \(\frac{1}{4}\)x³ : \(\left( {\frac{{ - 1}}{8}{\rm{x}}} \right)\) + x : \(\left( {\frac{{ - 1}}{8}{\rm{x}}} \right)\)

= \(\left( {\frac{1}{2}:\frac{{ - 1}}{8}} \right)\). x^{4 – 1} – \(\left( {\frac{1}{4}:\frac{{ - 1}}{8}} \right)\). x^{3 – 1} + \(\left( {1:\frac{{ - 1}}{8}} \right)\). x^{1 – 1}

= –4x³ + 2x² – 8