Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Ta có \(\left(\frac{3}{10}-\frac{4}{15}-\frac{7}{20}\right).\frac{5}{19}=\left(\frac{3}{10}-\frac{6}{20}-\frac{4}{15}-\frac{1}{20}\right).\frac{5}{19}=-\left(\frac{4}{15}+\frac{1}{20}\right).\frac{5}{19}\)
\(=-\frac{1}{5}\left(\frac{4}{3}+\frac{1}{4}\right).\frac{5}{19}=-\left(\frac{4}{3}+\frac{1}{4}\right).\frac{1}{19}=-\frac{19}{12}.\frac{1}{19}=-\frac{1}{12}\)
Lại có \(\left(\frac{1}{14}+\frac{1}{7}-\frac{3}{35}\right).\frac{-4}{3}=\left(\frac{1}{14}+\frac{1}{7}-\frac{5}{35}+\frac{2}{35}\right).\frac{-4}{3}=\left(\frac{1}{14}+\frac{2}{35}\right).\frac{-4}{3}\)
\(=\frac{1}{7}\left(\frac{1}{2}+\frac{2}{5}\right).\frac{-4}{3}=\left(\frac{1}{2}+\frac{2}{5}\right).\frac{-4}{21}=\frac{7}{10}.\frac{-4}{21}=\frac{-2}{15}\)
Khi đó \(\frac{\left(\frac{3}{10}-\frac{4}{15}-\frac{7}{20}\right).\frac{5}{19}}{\left(\frac{1}{14}+\frac{1}{7}-\frac{3}{35}\right).\frac{-4}{3}}=\frac{\frac{1}{12}}{-\frac{2}{15}}=-\frac{5}{8}\)
Làm lại :
\(\left(\frac{1}{14}+\frac{1}{7}-\frac{-3}{35}\right).\left(-\frac{4}{3}\right)=\left(\frac{1}{14}+\frac{1}{7}-\frac{5}{35}+\frac{2}{35}\right)\left(-\frac{4}{3}\right)=\left(\frac{1}{14}+\frac{2}{35}\right)\left(-\frac{4}{3}\right)\)
\(=\frac{1}{7}\left(\frac{1}{2}+\frac{2}{5}\right).\frac{-4}{3}=\frac{-4}{21}.\frac{9}{10}=\frac{-6}{35}\)
Khi đó A = \(\frac{\left(\frac{3}{10}-\frac{4}{15}-\frac{7}{20}\right).\frac{5}{19}}{\left(\frac{1}{14}+\frac{1}{7}-\frac{-3}{35}\right).\frac{-4}{3}}=\frac{-\frac{1}{12}}{-\frac{6}{35}}=\frac{35}{72}\)
3) C thiếu đề
4) \(D=\frac{1}{9}-\left|\frac{-5}{23}\right|-\left(\frac{-5}{23}+\frac{1}{9}+\frac{25}{7}\right)+\frac{50}{4}-\frac{7}{30}\)
\(D=\frac{1}{9}-\frac{5}{23}+\frac{5}{23}-\frac{1}{9}-\frac{25}{7}+\frac{50}{4}-\frac{7}{30}\)
\(D=\frac{1}{9}-\frac{1}{9}-\frac{5}{23}+\frac{5}{23}+\frac{-25}{7}+\frac{50}{4}-\frac{7}{30}\)
\(D=0+0+\frac{125}{14}-\frac{7}{30}\)
\(D=\frac{913}{105}\)
\(\frac{\left(\frac{3}{10}-\frac{4}{15}-\frac{7}{20}\right).\frac{5}{19}}{\left(\frac{1}{14}+\frac{1}{7}-\frac{-3}{35}\right).\frac{-4}{3}}=\frac{\left(\frac{18}{60}-\frac{16}{60}-\frac{21}{60}\right).\frac{5}{19}}{\left(\frac{5}{70}+\frac{7}{70}-\frac{-6}{70}\right).\frac{-4}{3}}\)
\(=\frac{-\frac{19}{60}.\frac{5}{19}}{\frac{3}{10}.\frac{-4}{3}}=\frac{-\frac{1}{12}}{-\frac{2}{5}}=\frac{5}{24}\)
a) \(2^5+8\left[\left(-2\right)^3:\frac{1}{2}\right]^0-\left(\frac{1}{2}\right)^3\times2+\left(-2\right)^3\)
\(=32+8\times1-\frac{1}{8}\times2+\left(-8\right)\)
\(=32+8-\frac{1}{4}+\left(-8\right)\)
\(=40-\frac{1}{4}+\left(-8\right)\)
\(=39\frac{3}{4}+\left(-8\right)\)
\(=31\frac{3}{4}\)
b vaf c mai minhf lamf, ht
\(\left(5-\frac{43}{10}\right)-\left(\frac{42}{19}-\left(\frac{7}{2}-\frac{59}{10}\right)\right)+\frac{42}{19}+\frac{59}{10}+\frac{4}{5}\)
\(=5-\frac{43}{10}-\left(\frac{42}{19}-\frac{7}{2}+\frac{59}{10}\right)+\frac{42}{19}+\frac{59}{10}+\frac{4}{5}\)
\(=5-\frac{43}{10}-\frac{42}{19}+\frac{7}{2}-\frac{59}{10}+\frac{42}{19}+\frac{59}{10}+\frac{4}{5}\)
\(=5-\frac{43}{10}+\frac{7}{2}+\frac{4}{5}\)
\(=5+\frac{35}{10}+\frac{8}{10}-\frac{43}{10}=5\)