Câu hỏi của Nkok_ Nhỏ_Dễ_Thươg

Question

Thực hiện phép tính

a) $\dfrac{1}{2}.\left(\dfrac{2}{9}+\dfrac{3}{7}-\dfrac{5}{27}\right)$                  b) $\left(\dfrac{-5}{28}+1,75+\dfrac{8}{35}\right):\left(-3\dfrac{9}{20}\right)$

c) \...

Quìn · Accepted Answer

a) $\dfrac{1}{2}.\left(\dfrac{2}{9}+\dfrac{3}{7}-\dfrac{5}{27}\right)$

$=\dfrac{1}{2}.\left(\dfrac{41}{63}-\dfrac{5}{27}\right)$

$=\dfrac{1}{2}.\dfrac{88}{189}$

$=\dfrac{44}{189}$

b) $\left(\dfrac{-5}{28}+1,75+\dfrac{8}{35}\right):\left(-3\dfrac{9}{20}\right)$

$=\left(\dfrac{11}{7}+\dfrac{8}{35}\right):\left(-3\dfrac{9}{20}\right)$

$=\dfrac{9}{5}:\left(-3\dfrac{9}{20}\right)$

$=\dfrac{9}{5}:\dfrac{-69}{20}$

$=\dfrac{-12}{23}$

c) $\dfrac{1}{3}.\dfrac{5}{7}-\dfrac{7}{27}.\dfrac{36}{14}$

$=\dfrac{5}{21}-\dfrac{7}{27}.\dfrac{36}{14}$

$=\dfrac{5}{21}-\dfrac{2}{3}$

$=\dfrac{-3}{7}$

d) $70,5-528:\dfrac{15}{2}$

$=70,5-\dfrac{352}{5}$

$=\dfrac{1}{10}$Câu trả lời: a) $\dfrac{1}{2}.\left(\dfrac{2}{9}+\dfrac{3}{7}-\dfrac{5}{27}\right)$