Giải Bài 5 trang 17

Đề bài

Thực hiện các phép chia:

a) $20x^3{y}^5:\left(5x^2{y}^2\right)$                                         

b) $18x^3{y}^5:\left[3{\left(-x\right)}^3{y}^2\right]$

Lời giải chi tiết

a) $20x^3{y}^5:\left(5x^2{y}^2\right)$

$$=\left(20:5\right).\left(x^3:x^2\right).\left(y^5:y^2\right)$$

$=4x{y}^3$

b) $18x^3{y}^5:\left[3{\left(-x\right)}^3{y}^2\right]$

$=18x^3{y}^5:\left[3.\left(-x^3\right)y^2\right]$

$=18x^3{y}^5:\left(-3x^3{y}^2\right)$

$=\left[18:\left(-3\right)\right].\left(x^3:x^3\right).\left(y^5:y^2\right)$

$=-6y^3$