Question

Bài 1: Tính
a) ( \(\dfrac{-3}{4}\)+ \(\dfrac{2}{5}\)) : \(\dfrac{3}{7}\)+ ( \(\dfrac{3}{5}\) + \(\dfrac{-9}{4}\)) :\(\dfrac{3}{7}\)
b) \(\dfrac{7}{8}\): ( \(\dfrac{2}{9}\)- \(\dfrac{1}{18}\)) + \(\dfrac{7}{8}\) : ( \(\dfrac{1}{36}\) - \(\dfrac{5}{12}\))
Cần gấp

Answer 1

a) \(\left(\dfrac{-3}{4}+\dfrac{2}{5}\right):\dfrac{3}{7}+\left(\dfrac{3}{5}+\dfrac{-9}{4}\right):\dfrac{3}{7}\)

\(=\left(\dfrac{-3}{4}+\dfrac{2}{5}+\dfrac{3}{5}+\dfrac{-9}{4}\right):\dfrac{3}{7}\)

\(=-2:\dfrac{3}{7}=\dfrac{-14}{3}\)

\(\dfrac{7}{8}:\left(\dfrac{2}{9}-\dfrac{1}{18}\right)+\dfrac{7}{8}:\left(\dfrac{1}{36}-\dfrac{5}{12}\right)\)

\(=\dfrac{7}{8}:\dfrac{1}{6}+\dfrac{7}{8}:\dfrac{-7}{18}\)

\(=\dfrac{7}{8}:\left(\dfrac{1}{6}+\dfrac{-7}{18}\right)=\dfrac{7}{8}:\dfrac{-2}{9}=\dfrac{63}{-16}\)

Answer 2

Bạn ấy làm phần a) rồi vậy mình xí phần b) nhé!

b,\(\dfrac{7}{8}:\left(\dfrac{2}{9}-\dfrac{1}{18}\right)+\dfrac{7}{8}:\left(\dfrac{1}{36}-\dfrac{5}{12}\right)\)

\(=\dfrac{7}{8}:\left(\dfrac{4}{18}-\dfrac{1}{18}\right)+\dfrac{7}{8}:\left(\dfrac{1}{36}-\dfrac{15}{36}\right)\)

\(=(\dfrac{7}{8}:\dfrac{1}{6})+(\dfrac{7}{8}:-\dfrac{7}{18})\)

\(=3\)