\(A=1\frac{1}{2}\cdot1\frac{1}{3}\cdot1\frac{1}{4}\cdot...\cdot1\frac{1}{2015}\)
\(\Rightarrow A=\frac{3}{2}\cdot\frac{4}{3}\cdot\frac{5}{4}\cdot...\cdot\frac{2016}{2015}\)
\(\Rightarrow A=\frac{3\cdot4\cdot5\cdot...\cdot2016}{2\cdot3\cdot4\cdot...\cdot2015}=\frac{2016}{2}=1008\)
Vậy A = 1008
rút gọn biểu thức: A =\(1\frac{1}{2}\times1\frac{1}{3}\times1\frac{1}{4}\times........\times1\frac{1}{2015}\)
Rút gọn biểu thức \(A=\frac{3}{4}\times\frac{8}{9}\times\frac{15}{16}\times\frac{24}{25}\times...\times\frac{899}{900}\)
Rút gọn biểu thức A = \(1\frac{1}{2}\)x \(1\frac{1}{3}\)x \(1\frac{1}{4}\)x ...x 1\(\frac{1}{2015}\).
a) Tính :
\(3\frac{1}{2}+\frac{2014}{2015}-0,5+\frac{1}{2015}\)
b) Tìm x :
\(85\%\times x+25\%\times x=110\)
Tìm x :
a) x - 5 = 49 : 7
b) 2 \(\times\) x + 6 = 24
c) \(\frac{1}{3}:x+\frac{1}{2}=5\)
d) \(\frac{1}{6}\times x-\frac{1}{3}=2\)
e)\(\frac{x}{27}=\frac{3}{x}\left(vớix\in N\right)\)
g) 1200 : 24 - ( 17 - x ) = 36
h) 674 - ( 12 + x ) = 427
k) 36 \(\times\)( x - 9 ) = 900
m) 1,2 : x + 3,8 : x = 2,5
n) \(\left(\frac{1}{2\times4}+\frac{1}{4\times6}+\frac{1}{6\times8}+\frac{1}{8\times10}\right)\times x=\frac{1}{3}\)
Mik đang cần gấp
Tìm x , biết
a, x-\(\frac{1}{2}\)= \(\frac{-3}{4}\)
b. \(\frac{5}{2}\times x+\frac{2}{3}=3\frac{1}{6}\)
\(A=\frac{1}{1\cdot2\cdot3}+\frac{1}{2\cdot3\cdot4}+\frac{1}{3\cdot4\cdot5}+...+\frac{1}{98\cdot99\cdot100}=\frac{1}{k}\times\left(\frac{1}{1\cdot2}-\frac{1}{99\cdot100}\right)\)
Tìm giá trị của k.
A=\(1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{2015}-\frac{1}{2016}+\frac{1}{2017}\)
B=\(\frac{1}{1009}+\frac{1}{1010}+\frac{1}{1011}+...+\frac{1}{2016}+\frac{1}{2017}\)
tính (A-B)^2017
Tính giá trị của biểu thức:
a)\(A=\) \(\frac{\frac{1}{3}+\frac{1}{9}-\frac{1}{27}}{\frac{5}{3}+\frac{5}{9}-\frac{5}{27}}\)
b)\(B=\frac{\frac{2}{3}-\frac{1}{4}+\frac{5}{11}}{\frac{5}{12}+1-\frac{7}{11}}\)
