Làm tính chia:

$$\begin{gathered} a) (25x^5 – 5x^4 + 10x^2) : 5x^2; \\ b) (15x^3{y}^2 – 6x^{2}y – 3x^2{y}^2) : 6x^{2}y. \end{gathered}$$

Giải:

$$\begin{gathered} a) (25x^5 – 5x^4 + 10x^2) : 5x^2 \\ = (25x^5 : 5x^2 ) - (5x^4 : 5x^2 ) + (10x^2 : 5x^2 ) \\ = 5x^3 – x^2 + 2 \end{gathered}$$

$$\begin{gathered} b) (15x^3{y}^2 – 6x^{2}y – 3x^2{y}^2) : 6x^{2}y \\ = (15x^3{y}^2 : 6x^{2}y) + (– 6x^{2}y : 6x^{2}y) + (– 3x^2{y}^2 : 6x^{2}y) \\ = \frac{15}{6}xy - 1 - \frac{3}{6}y \\ = \frac{5}{2}xy -\frac{1}{2} y - 1. \end{gathered}$$