Đáp án:
Giải thích các bước giải:
`a)MSC:35`
$\dfrac{2}{5}=$ $\dfrac{2.7}{5.7}=$ $\dfrac{14}{35}$
$\dfrac{5}{7}=$ $\dfrac{5.5}{7.5}=$ $\dfrac{25}{35}$
`b)MSC:333`
$\dfrac{6}{9}=$ $\dfrac{6.37}{9.37}=$ $\dfrac{222}{333}$
$\dfrac{12}{37}=$ $\dfrac{12.9}{37.9}=$ $\dfrac{108}{333}$