\(\dfrac{2}{1.5}\)+\(\dfrac{2}{5.9}\)+\(\dfrac{2}{9.13}\)+.................+\(\dfrac{2}{2013+2017}\)
=\(\dfrac{1}{1}\)-\(\dfrac{1}{5}\)+\(\dfrac{1}{5}\)-\(\dfrac{1}{9}\)+\(\dfrac{1}{9}\)-\(\dfrac{1}{13}\)+...................+\(\dfrac{1}{2013}-\dfrac{1}{2017}\)
=\(\dfrac{1}{1}-\dfrac{1}{2017}\)
=\(\dfrac{2017}{2017}+\dfrac{-1}{2017}\)
=\(\dfrac{2016}{2017}\)
Bài 1 : Tính
a , `5 + 5^2 + 5^3 + ... + 5^99`
b, `\frac{1}{1.5} + \frac{1}{5.9} + ... + \frac{1}{17.21}`
CHo A=1+4+4 mũ 2+.......+4 mũ 2017 và B=4 mũ 2018:6. Tính 2B-A
cho tổng T= \(\dfrac{2}{2^1}+\dfrac{3}{2^2}+\dfrac{4}{2^3}\) +...+\(\dfrac{2016}{2^{2015}}+\dfrac{2017}{2^{2016}}\)
so sánh T với 3
Tính:A=\(\dfrac{1.3}{2^2}.\dfrac{2.4}{3^2}\dfrac{3.5}{4^2}.\dfrac{4.6}{5^2}...\dfrac{2016.2018}{2017^2}\)
Tìm tập hợp các số nguyên m biết:
\(2017^0\)-11≤3m≤\(\left(\dfrac{2016}{2017}-\dfrac{2017}{2018}\right).\left(\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{6}\right).\left(-3^2+9\right)\)
Cho A=1+\(\dfrac{1}{2}\)+\(\dfrac{1}{2^2}\)+\(\dfrac{1}{2^3}\)+...+\(\dfrac{1}{2^{2013}}\). So sánh A và 2
Bỏ ngoặc rồi tính
( - 2017 ) - ( 2 - 2017 ) - [ - 28 - ( - 2020 ) ]
Giúp mình với
Bài 1: Thực hiện phép tính:
a) [3. (-5)- (-2013)- 12. 3]: (-2)- 2014^0 +3^3
b) (-7- 28): (-7) + 12^4 : (-12)^3 - (-1)^2n+1
c) -8^3. (-2)^5 + 6^7 : 6^5 - (-2013)^0 - (-5)^3
( 1+\(\dfrac{2}{3}\) ) . ( 1+\(\dfrac{2}{5}\) ) . (1+\(\dfrac{2}{7}\) ) ....(1+\(\dfrac{2}{2017}\) )
