Đáp án:
a/$\frac{49}{20}$
b/ $\frac{-2}{ 3}$
c/ $\frac{3364}{2019}$
Giải thích các bước giải:
a/ $\frac{7}{4}$-$\frac{7}{10}$+$\frac{7}{5}$ (MC:20)
= $\frac{7.5}{4.5}$ - $\frac{7.2}{10.2}$ +$\frac{7.4}{5.4}$
= $\frac{7.5 -7.2 + 7.4}{20}$
= $\frac{7.7}{20}$
=$\frac{49}{20}$
b/ $\frac{8}{24}$-1
= $\frac{8}{24}$-$\frac{24}{24}$
= $\frac{-16}{24}$
=$\frac{-2}{3}$
c/ $\frac{2018}{2019}$+$\frac{2}{3}$
= $\frac{2018}{2019}$+$\frac{1346}{2019}$
= $\frac{2018+1346}{2019}$
= $\frac{3364}{2019}$
