Tính: -x^2.(1/3 x^2 - x - 1/4) =
Giải thích
–x2.\(\left( {\frac{1}{3}{{\rm{x}}^2} - {\rm{x}} - \frac{1}{4}} \right)\) = –x2. \(\frac{1}{3}\)x2 – x2. (–x) – x2. \(\frac{{ - 1}}{4}\) = \(\frac{{ - 1}}{3}\)x4 + x3 + \(\frac{1}{4}\)x2
–x2.\(\left( {\frac{1}{3}{{\rm{x}}^2} - {\rm{x}} - \frac{1}{4}} \right)\) = –x2. \(\frac{1}{3}\)x2 – x2. (–x) – x2. \(\frac{{ - 1}}{4}\) = \(\frac{{ - 1}}{3}\)x4 + x3 + \(\frac{1}{4}\)x2