Đáp án:
a) $2$
b) $0$
Giải thích các bước giải:
a) $\dfrac{24}{27}$ +$\dfrac{9}{45}$ + $\dfrac{26}{47}$ + $\dfrac{4}{5}$
= ($\dfrac{24}{27}$ + $\dfrac{26}{47}$) + ($\dfrac{9}{45}$+ $\dfrac{4}{5}$)
= $1$+ $1$
= $2$
b) $\dfrac{15}{12}$ + $\dfrac{5}{13}$ - $\dfrac{3}{12}$ - $\dfrac{18}{13}$
= ($\dfrac{15}{12}$ - $\dfrac{3}{12}$) + ($\dfrac{5}{13}$ - $\dfrac{18}{13}$)
= $1$ - $1$
= $0$