Quy đồng mẫu thức các phân số sau: 24/14x^2y; 14/21xy^5

* Hướng dẫn giải

$\frac{25}{14{\mathrm{x}}^2\mathrm{y}};\frac{14}{21{\mathrm{xy}}^5}$

Nhân tử phụ:

$\begin{array}{l}42{\mathrm{x}}^2{\mathrm{y}}^5:14{\mathrm{x}}^2\mathrm{y}=3{\mathrm{y}}^4\\ 42{\mathrm{x}}^2{\mathrm{y}}^5:21{\mathrm{xy}}^5=2\mathrm{x}\end{array}$

Quy đồng:

$\begin{array}{l}\frac{25}{14{\mathrm{x}}^2\mathrm{y}}=\frac{25.3{\mathrm{y}}^4}{42{\mathrm{x}}^2{\mathrm{y}}^5}=\frac{75{\mathrm{y}}^4}{42{\mathrm{x}}^2{\mathrm{y}}^5}\\ \frac{14}{21{\mathrm{xy}}^5}=\frac{14.2\mathrm{x}}{42{\mathrm{x}}^2{\mathrm{y}}^5}=\frac{28\mathrm{x}}{42{\mathrm{x}}^2{\mathrm{y}}^5}\end{array}$