Đáp án:
Giải thích các bước giải:
a)
$\dfrac{7}{4}$ × $\dfrac{7}{6}$ + $\dfrac{3}{4}$
= $\dfrac{49}{24}$ + $\dfrac{3}{4}$
= $\dfrac{49}{24}$ + $\dfrac{18}{24}$
= $\dfrac{49+18}{24}$
= $\dfrac{67}{24}$
b)
$\dfrac{8}{5}$ - $\dfrac{1}{2}$ + $\dfrac{3}{4}$ + $\dfrac{7}{8}$
= $\dfrac{8}{5}$ + $\dfrac{7}{8}$ + + $\dfrac{1}{4}$
= $\dfrac{64}{40}$ + + $\dfrac{35}{40}$ + + $\dfrac{10}{40}$
= $\dfrac{64 + 35 + 10}{40}$
= $\dfrac{109}{40}$
xin câu tl hay nhất nhá