Đáp án:
Giải thích các bước giải:
a)
$\dfrac{-7}{16}$ , $\dfrac{3}{20}$ và $\dfrac{-9}{20}$
MSC là :80
$\dfrac{-7}{16}$ = $\dfrac{-7.5}{16.5}$ = $\dfrac{-35}{80}$
$\dfrac{3}{20}$ = $\dfrac{3.4}{20.4}$ = $\dfrac{12}{80}$
$\dfrac{-9}{20}$ = $\dfrac{-9.4}{20.4}$ = $\dfrac{-36}{80}$
b)
$\dfrac{-5}{9}$, $\dfrac{14}{15}$ và $\dfrac{-23}{30}$
MSC là : 90
$\dfrac{-5}{9}$ = $\dfrac{-5.10}{9.10}$ $\dfrac{-50}{90}$
$\dfrac{14}{15}$ = $\dfrac{14.6}{15.6}$ = $\dfrac{84}{90}$
$\dfrac{-23}{30}$ = $\dfrac{-23.3}{30.3}$ = $\dfrac{-69}{90}$
