Thực hiện phép tính:
\(\left(1-\frac{1}{2}\right)+\left(1-\frac{2}{3}\right)+...+\left(1-\frac{1}{2015.2016}\right)\)
Thực hiện phép tính :
\([6.\left(-\frac{1}{3}\right)^2-3\left(-\frac{1}{3}\right)+1]:\left(-\frac{1}{3}-1\right)\left(=-2\right)\)
Thực hiện phép tính
a) \(\left[6.\left(-\frac{1}{3}\right)^2-3.\left(-\frac{1}{3}\right)+1\right]:\left(-\frac{1}{3}-1\right)\)
b) \(\frac{\left(\frac{2}{3}\right)^3.\left(-\frac{3}{4}\right)^2.\left(-1\right)^{2003}}{\left(\frac{2}{5}\right)^2.\left(-\frac{5}{12}\right)^3}\)
Thực hiện phép tính:\(\left(1-\frac{1}{2018}\right).\left(1-\frac{2}{2018}\right).\left(1-\frac{3}{2018}\right)...\left(1-\frac{2020}{2018}\right)\)
Thực hiện phép tính :
a, A =\(\left(1:\frac{5^2}{10^2}\right).\left(1\frac{1}{1}\right)^2+25.\left[1:\left(\frac{4}{3}\right)^2:\left(\frac{5}{4}\right)^3\right]:\left(1:\frac{-8}{27}\right)\)
b, B =\(\left(1-\frac{1}{2^2}\right).\left(1-\frac{1}{3^2}\right).\left(1-\frac{1}{4^2}\right)...\left(1-\frac{1}{100^2}\right)\)
a) \(A=\left(1:\frac{1}{4}\right).4+25\left(1:\frac{16}{9}:\frac{125}{64}\right):\left(-\frac{27}{8}\right)\)
\(=4.4+25.\frac{36}{125}:\frac{-27}{8}\)
\(=16-\frac{32}{15}=\frac{240}{15}-\frac{32}{15}=\frac{208}{15}\)
Thực hiện các phép tính sau:
\(\frac{\left(-5\right)^3.\left(-0.9\right)^2}{\left(1\frac{1}{2}\right)^4.\left(-3\frac{1}{3}\right)^3.\left(-1\right)^7}\)
Thực hiện phép tính:
\(\left(\frac{-1}{2}\right)^3-2.\left(\frac{-1}{2}\right)^2+3.\left(\frac{-1}{2}\right)+1\)
= (-1/2)3-2+1.2.3+1
=1/4.6+1
=3/2+1
=5/2
Thực hiện phép tính
\(A=\left(1-\frac{1}{1+2}\right)\left(1-\frac{1}{1+2+3}\right)\left(1-\frac{1}{1+2+3+4}\right)...\left(1-\frac{1}{1+2+3+.+2006}\right)\)
\(A=(1-\frac{1}{1+2})(1-\frac{1}{1+2+3})(1-\frac{1}{1+2+3+4})...(1-\frac{1}{1+2+3+...+2006})\)
\(A=(1-\frac{1}{3})(1-\frac{1}{6})(1-\frac{1}{10})...(1-\frac{1}{2013021})\)
\(A=\frac{2}{3}\cdot\frac{5}{6}\cdot\frac{9}{10}....\frac{2013020}{2013021}\)
Sorry bạn máy tính mình có chút vấn đề để mk làm tiếp :
\(A=\frac{4}{6}\cdot\frac{10}{12}\cdot\frac{18}{20}....\cdot\frac{4026040}{4026042}\)
\(A=\frac{1\cdot4}{2\cdot3}\cdot\frac{2\cdot5}{3\cdot4}\cdot\frac{3\cdot6}{4\cdot5}\cdot...\cdot\frac{2005\cdot2008}{2006\cdot2007}\)
\(A=\frac{1\cdot2\cdot3\cdot...\cdot2005}{2\cdot3\cdot4\cdot...\cdot2006}\cdot\frac{4\cdot5\cdot6\cdot...\cdot2008}{3\cdot4\cdot5\cdot...\cdot2007}\)
\(A=\frac{1}{2006}\cdot\frac{2008}{3}=\frac{1004}{3009}\)
P/S : Hoq chắc :>
Thực hiện phép tính : \(\left(1\frac{1}{1+2}\right).\left(1\frac{1}{1+2+3}\right)...\left(1\frac{1}{1+2+3+...+2018}\right)\)
Thực hiện phép tính:
\(\left(1+\frac{2}{4}\right).\left(1+\frac{2}{10}\right).\left(1+\frac{2}{18}\right).........\left(1+\frac{2}{270}\right)-2,\left(6\right)\)