tính nhanh
A = \(\frac{-7}{813}\)+ 496 . (\(\frac{-7}{813}\)) + (\(\frac{-7}{813}\)) . 316
B= \(\frac{-9}{10}\).\(\frac{5}{14}\)+ \(\frac{1}{10}\). (\(\frac{-9}{2}\))+ \(\frac{1}{7}\). (\(\frac{-9}{10}\))
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
= \(\frac{-7}{813}.\left(1+496+316\right)=\frac{-7}{813}.813=-7\)
\(\frac{-9}{10}.\frac{5}{14}+\frac{1}{10}.\left(\frac{-9}{2}\right)+\frac{1}{7}.\frac{-9}{10}\)
\(=\frac{-9}{10}.\frac{5}{14}+\frac{1}{7}.\frac{-9}{10}+\frac{1}{10}.\left(\frac{-9}{2}\right)\)
\(=\frac{-9}{10}.\left(\frac{5}{14}+\frac{1}{7}\right)+\frac{1}{10}.\left(\frac{-9}{2}\right)\)
\(=\frac{-9}{10}.\frac{1}{2}+\frac{1}{10}.\left(\frac{-9}{2}\right)\)
\(=\left(\frac{-9}{10}+\frac{1}{2}\right)^2\)
\(=\left(\frac{-9}{10}+\frac{5}{10}\right)^2\)
\(=\left(\frac{-2}{5}\right)^2\)
\(=\frac{4}{25}\)
\(M=\frac{\left(-7\right).15.9.15.14}{9.49.7.15}=\frac{-15.2}{7}=\frac{-30}{7}.\)
\(N=\frac{200}{189}+\frac{1}{14}=\)1.12962962963
\(M=\left(\frac{-7}{9}\cdot\frac{9}{7}\right)\cdot\left(\frac{15}{49}\cdot\frac{14}{15}\right)\cdot15\)
\(M=\left(-1\right)\cdot\frac{2}{7}\cdot15\)
\(M=\frac{-30}{7}\)
\(N=\frac{5}{9}\cdot\frac{4}{7}\cdot\frac{10}{3}+\frac{3}{9}\cdot\frac{3}{7}\cdot\frac{1}{2}\)
\(N=\frac{200\cdot2}{189\cdot2}+\frac{9\cdot3}{126\cdot3}\)
\(N=\frac{400}{378}+\frac{27}{378}\)
\(N=\frac{61}{51}\)
T i ck nha
\(a,\frac{7}{12}\cdot\frac{6}{11}+\frac{7}{12}\cdot\frac{5}{11}+2\frac{7}{12}\)
\(=\frac{7}{12}\cdot\left(\frac{6}{11}+\frac{5}{11}\right)+2\frac{7}{12}\)
\(=\frac{7}{12}+\frac{31}{12}\)
\(=\frac{38}{12}=\frac{19}{6}\)
\(b,\frac{-5}{9}\cdot\frac{-6}{13}+\frac{5}{-9}\cdot\frac{-5}{13}-\frac{5}{9}\)
\(=\frac{-5}{9}\cdot\frac{-6}{13}+\frac{-5}{9}\cdot\frac{-5}{13}+\frac{-5}{9}\cdot1\)
\(=\frac{-5}{9}\cdot\left(\frac{-6}{13}+\frac{-5}{13}+1\right)\)
\(=\frac{-5}{9}\cdot\left(\frac{-11}{13}+1\right)\)
\(=\frac{-5}{9}\cdot\frac{2}{13}\)
\(=\frac{-10}{117}\)
\(c,\)\(0,8\cdot\frac{-15}{14}-\frac{4}{5}\cdot\frac{13}{14}-1\frac{2}{5}\)
\(=\frac{4}{5}\cdot\frac{-15}{14}-\frac{4}{5}\cdot\frac{13}{14}-\frac{7}{5}\)
\(=\frac{4}{5}\cdot\left(\frac{-15}{14}-\frac{13}{14}\right)-\frac{7}{5}\)
\(=\frac{4}{5}\cdot\left(-2\right)-\frac{7}{5}\)
\(=\frac{-8}{5}-\frac{7}{5}\)
\(=-3\)
\(d,\)\(75\%\cdot\frac{6}{7}+5\%\cdot\frac{6}{7}+\frac{7}{10}\cdot1\frac{1}{7}\)
\(=\frac{3}{4}\cdot\frac{6}{7}+\frac{1}{20}\cdot\frac{6}{7}+\frac{7}{10}\cdot\frac{8}{7}\)
\(=\left(\frac{3}{4}+\frac{1}{20}\right)\cdot\frac{6}{7}+\frac{7}{10}\cdot\frac{8}{7}\)
\(=\frac{4}{5}\cdot\frac{6}{7}+\frac{4}{5}\cdot1\)
\(=\frac{4}{5}\cdot\left(\frac{6}{7}+1\right)\)
\(=\frac{4}{5}\cdot\frac{13}{7}\)
\(=\frac{52}{35}\)
a)7/12.6/11+7/12.5/11-2.7/12
=7/12(6/11+5/11-2)
=7/12(1-2)
=7/12.(-1)
=-7/12
a= (\(\frac{2}{5}\)+\(\frac{2}{9}\)+\(\frac{2}{11}\)\(\times\)\(\frac{5}{7}\)\(+\frac{7}{9}\)\(+\frac{7}{11}\)\()\)
Tính nhanh
\(\frac{-9}{10}\).\(\frac{5}{14}+\frac{1}{10}.\frac{-9}{2}\)+ \(\frac{1}{7}.\frac{-9}{2}\)
\(=\frac{-9}{2}.\frac{5}{70}+\frac{1}{10}.\frac{-9}{2}+\frac{1}{7}.\frac{-9}{2}\Rightarrow\)\(\frac{-9}{2}.\left(\frac{5}{70}+\frac{1}{10}+\frac{1}{7}\right)\Rightarrow\frac{-9}{2}.\frac{11}{35}=\frac{-99}{70}\)
a) \(A=\frac{-7}{813}+496.\left(\frac{-7}{813}\right)+\left(\frac{-7}{813}\right).316\)
\(=\frac{-7}{813}.\left(1+496+316\right)\)
\(=\frac{-7}{813}.813\)
\(=-7\)
b) \(B=\frac{-9}{10}.\frac{5}{14}+\frac{1}{10}.\left(\frac{-9}{2}\right)+\frac{1}{7}.\left(\frac{-9}{10}\right)\)
\(=\frac{-9}{10}.\left(\frac{5}{14}+\frac{1}{2}+\frac{1}{7}\right)\)
\(=\frac{-9}{10}.1\)
\(=\frac{-9}{10}\)