Tính
1, -2.\(\dfrac{-38}{21}\).\(\dfrac{-7}{4}\).\(\dfrac{-3}{8}\)
2, (\(-\dfrac{2}{3}\)+\(\dfrac{3}{7}\)):\(\dfrac{4}{5}\)+(\(-\dfrac{1}{3}\)+\(\dfrac{4}{7}\)):\(\dfrac{4}{5}\)
3, \(\dfrac{5}{9}\):(\(\dfrac{1}{11}\)-\(\dfrac{5}{22}\))+\(\dfrac{5}{9}\):(\(\dfrac{1}{15}\)-\(\dfrac{2}{3}\))
giải hộ mk vs ạ...
Đọc tiếp
Tính
1, -2.\(\dfrac{-38}{21}\).\(\dfrac{-7}{4}\).\(\dfrac{-3}{8}\)
2, (\(-\dfrac{2}{3}\)+\(\dfrac{3}{7}\)):\(\dfrac{4}{5}\)+(\(-\dfrac{1}{3}\)+\(\dfrac{4}{7}\)):\(\dfrac{4}{5}\)
3, \(\dfrac{5}{9}\):(\(\dfrac{1}{11}\)-\(\dfrac{5}{22}\))+\(\dfrac{5}{9}\):(\(\dfrac{1}{15}\)-\(\dfrac{2}{3}\))
giải hộ mk vs ạ :(
\(2.\dfrac{-38}{21}.\dfrac{7}{4}.\dfrac{-3}{8}\)
\(=\) \(\left(-2.\dfrac{-7}{4}.\dfrac{-3}{8}\right).\dfrac{-38}{21}\)
\(=\)\(\left(\dfrac{7}{2}.\dfrac{-3}{8}\right).\dfrac{-38}{21}\)
= \(\dfrac{-21}{16}.\dfrac{-38}{21}\)
= \(\dfrac{-38}{-16}=\dfrac{19}{8}\)
\(\left(-\dfrac{2}{3}+\dfrac{3}{7}\right)\div\dfrac{4}{5}+\left(-\dfrac{1}{3}+\dfrac{4}{7}\right)\div\dfrac{4}{5}\)
= \(\left(\dfrac{-2}{3}+\dfrac{3}{7}+\dfrac{-1}{3}+\dfrac{4}{7}\right)\div\dfrac{4}{5}\)
= \(\left[\left(-\dfrac{2}{3}+-\dfrac{1}{3}\right)+\left(\dfrac{3}{7}+\dfrac{4}{7}\right)\right]\div\dfrac{4}{5}\)
= \(\left(-1+1\right)\div\dfrac{4}{5}\)
= \(0\div\dfrac{4}{5}\)
= \(0\)
\(\dfrac{5}{9}\div\left(\dfrac{1}{11}-\dfrac{5}{22}\right)+\dfrac{5}{9}\div\left(\dfrac{1}{15}-\dfrac{2}{3}\right)\)
= \(\dfrac{5}{9}\div\left(\dfrac{2}{22}-\dfrac{5}{22}\right)+\dfrac{5}{9}\div\left(\dfrac{1}{15}-\dfrac{10}{15}\right)\)
= \(\dfrac{5}{9}\div\dfrac{-3}{22}+\dfrac{5}{9}\div\dfrac{-9}{15}\)
= \(\dfrac{5}{9}.\dfrac{-3}{22}+\dfrac{5}{9}.\dfrac{-15}{9}\)
= \(\dfrac{5}{9}.\left(-\dfrac{22}{3}+-\dfrac{15}{9}\right)\)
= \(\dfrac{5}{9}.\dfrac{-27}{3}\)
= \(-5\)