\(\frac{-4}{5}.13\frac{1}{3}-\frac{4}{5}.\left(-13\frac{1}{2}\right)\)
\(=\frac{4}{5}.\left(-13\frac{1}{3}\right)-\frac{4}{5}.\left(-13\frac{1}{2}\right)\)
\(=\frac{4}{5}\left[\left(-3\frac{1}{2}\right)-\left(-3\frac{1}{2}\right)\right]\)
\(=\frac{4}{5}.0\)
\(=0\)
Tính tổng:
\(M=-\frac{4}{1\cdot5}-\frac{4}{5\cdot9}-\frac{4}{9\cdot13}-...-\frac{4}{\left(n+4\right)\cdot n}\)
tình hợp lí:
\(\frac{\left(\frac{1}{5}-\frac{2}{7}\right)\cdot\frac{3}{4}-\frac{3}{4}\cdot\left(\frac{1}{3}-\frac{2}{7}\right)}{\frac{1}{5}\cdot\frac{2}{7}-\frac{1}{3}\cdot\left(\frac{2}{7}+\frac{3}{9}\right)+\frac{3}{9}+\frac{1}{5}}\)
\(\left[6\cdot\left(-\frac{1}{3}\right)^2-3\cdot\left(-\frac{1}{3}\right)+1\right]:\left(-\frac{1}{3}-1\right)\)
\(\frac{\left(\frac{2}{3}\right)^3\cdot\left(-\frac{3}{4}\right)^2\cdot\left(-1\right)^{2003}}{\left(\frac{2}{5}\right)^2\cdot\left(-\frac{5}{12}\right)^3}\)
a)\(\frac{15}{12}+\frac{5}{13}-\frac{3}{12}-\frac{18}{13}\)
b)\(\frac{11}{24}-\frac{5}{41}+\frac{13}{24}+0,5-\frac{36}{41}\)
c)\(\left(-\frac{3}{4}+\frac{2}{3}\right):\frac{5}{11}+\left(-\frac{1}{4}+\frac{1}{3}\right):\frac{5}{11}\)
d)\(\left(-3\right)^2\cdot\left(\frac{3}{4}-0,25\right)-\left(3\frac{1}{2}-1\frac{1}{2}\right)\)
e)\(\frac{13}{25}+\frac{6}{41}-\frac{38}{25}+\frac{35}{41}-\frac{1}{2}\)
tinh hop li :
\(\frac{\left(\frac{1}{5}-\frac{2}{7}\right)\cdot\frac{3}{4}-\frac{3}{4}\cdot\left(\frac{1}{3}-\frac{2}{7}\right)}{\frac{1}{5}\cdot\frac{2}{7}-\frac{1}{3}\cdot\left(\frac{2}{7}+\frac{3}{9}\right)+\frac{3}{9}+\frac{1}{5}}\)
\(\left(\frac{1}{7}\cdot x-\frac{2}{7}\right)\cdot\left(-\frac{1}{5}\cdot x+\frac{3}{5}\right)\cdot\left(\frac{1}{3}\cdot x+\frac{4}{3}\right)=0\)
TÌM x
\(\left(\left(\frac{3}{4}\cdot x+5\right)-\left(\frac{2}{3}\cdot x-4\right)-\left(\frac{1}{6}\cdot x+1\right)\right)=\left(\frac{1}{3}\cdot x+4\right)-\left(\frac{1}{3}-3\right)\)
Tính \(A=\frac{\left(1+2+3+...+100\right)\cdot\left(\frac{1}{2}-\frac{1}{3}-\frac{1}{4}-\frac{1}{5}\right)\cdot\left(2,4\cdot42-21\cdot4,8\right)}{1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{100}}\)
Tính:
a)\([\left(-\frac{1}{2}\right)^3-\left(\frac{3}{4}\right)^3\cdot\left(-2\right)^2]:[2\cdot\left(-1\right)^5+\left(\frac{3}{4}\right)^2-\frac{3}{8}\)
b)\([\left(\frac{4}{3}\right)^{-2}\left(\frac{3}{4}\right)^4]:\left(\frac{3}{2}\right)^6\)
help me!!!!!!!!!!!!!!
