Tính: 9/10 x 5/6

* Hướng dẫn giải

$\frac{9}{10}x\frac{5}{6}\mathit{=}\frac{\mathit{9}\mathit{x}\mathit{5}}{\mathit{10}\mathit{x}\mathit{6}}\mathit{=}\frac{\mathit{3}\mathit{x}\mathit{3}\mathit{x}\mathit{5}}{\mathit{2}\mathit{x}\mathit{5}\mathit{x}\mathit{2}\mathit{x}\mathit{3}}\mathit{=}\frac{\mathit{3}}{\mathit{2}\mathit{x}\mathit{2}}\mathit{=}\frac{\mathit{3}}{\mathit{4}}$