b1 :tính
a) N = (1/2 - 1). (1/3 - 1). (1/4 - 1) .... (1/2016 - 1). (1/2017 - 1)
b) P = (-1/1/2). (-1/1/3). (-1/1/4) ... (-1/1/2015). (2016/01/01)
c) Q = 1/13 + 3 / 13,23 + 3 / 23,33 + ... + 3 / 2013,2023
d) R = 1 / 2017.2016-1 / 2016.2015-1 / 2015.2014 - ... -. 1 / 3.2 - 1/ 2.1
( chú ý : / là phần nha )
B1:Tính
a)(-2/3+3/7):4/5+(-1/3+4/7):4/5
b)5/9:(1/11-5/22)+5/9:(1/15-2/3)
c)4^2.4^3/4^10
d)(0,6)^5/(0,2)^6
e)2^7.9^3/6^5.8^2
g)6^3+3.6^2+3^3/-13
h)(3/7+1/2)^2
i)(3/4-5/6)^2
k)5^4.20^44/25^5.4^5
l)(-10/3)^5.(-6/5)^4
f)(1+2/3-1/4).(4/5-3/4)^2
m)2:(1/2-2/3)^3
n)9.9.(-1/3)^3+1/3
y)(4.2^5):(2^3.1/16)
Tính:
a) S=1.2+2.3+3.4+...+99.100
b) B=\(\dfrac{49^{24}.125^{17}.2^8-5^{30}.7^{49}.4^5}{5^{29}.16^2.7^{48}}\)
c) C=\(\left(\dfrac{1}{3}+\dfrac{1}{3^2}+\dfrac{1}{3^3}+\dfrac{1}{3^4}\right).3^5+\left(\dfrac{1}{3^5}+\dfrac{1}{3^6}+\dfrac{1}{3^7}+\dfrac{1}{3^8}\right).3^9+...+\left(\dfrac{1}{3^{97}}+\dfrac{1}{3^{98}}+\dfrac{1}{3^{99}}+\dfrac{1}{3^{100}}\right).3^{101}\)
d) D= \(3-3^2+3^3-3^4+...+3^{2017}-3^{2018}\)
Tính giá trị của biểu thức \(\left(S-P\right)^{2015}+\left(S-P\right)^{2016}\)
\(S=1-\dfrac{1}{2}+\dfrac{1}{3}-\dfrac{1}{4}+.....+\dfrac{1}{2003}-\dfrac{1}{2004}+\dfrac{1}{2005}\)
\(P=\dfrac{1}{1008}+\dfrac{1}{1009}+\dfrac{1}{1010}+......+\dfrac{1}{2014}+\dfrac{1}{2015}\)
GIÚP MÌNH NHANH NHÉ !
Bài 8: Viết các biểu thức sau đây dưới dạng a^n (a e Q; n e N*)
a, 9. 3^5. 1/81 ; b, 8.2^4: (2^3.1/16) ; c, 3^2.3^5:1/27 ; d, 125.5^2.1/625
Bài 12: Tính:
a) (-0,1)^2.(-0,1)^3 ; b) 125^2 : 25^3 ; c) (7^3)^2 : (7^2)^3 ; d) (-2)^3+2^2+(-1)^20+(-2)^0 ; e) 2^4+8.[(-3)^2 : 1/2]^0-2^-2.4+(-2)^-2
so sánh x và y biết : \(x=\dfrac{2016^{2017}+1}{2016^{2016}+1}\) và \(y=\dfrac{2016^{2016}+1}{2016^{2015}+1}\)
So sánh:
a, \(\dfrac{1}{3}+\dfrac{1}{3^2}+...+\dfrac{1}{3^{50}}\) và \(\dfrac{1}{2}\)
b, \(\dfrac{1}{4}-\dfrac{1}{4^2}+\dfrac{1}{4^3}-...+\dfrac{1}{4^{99}}\) và \(\dfrac{1}{12}\)
c, \(\dfrac{1}{3}+\dfrac{2}{3^2}+\dfrac{3}{3^3}+...+\dfrac{50}{3^{50}}\) và \(\dfrac{3}{4}\)
a,\(\frac{-1}{24}-\left[\frac{1}{4}-\left(\frac{1}{2}-\frac{7}{8}\right)\right]\)
b,\(\left[\frac{5}{7}-\frac{7}{5}\right]-\left[\frac{1}{2}-\left(\frac{-2}{7}-\frac{1}{10}\right)\right]\)
c,\(\left(\frac{-1}{2}\right)-\left(\frac{-3}{5}\right)+\left(\frac{-1}{9}\right)+\frac{1}{71}-\left(\frac{-2}{7}\right)+\frac{4}{35}-\frac{7}{8}\)
d,\(\left(3-\frac{1}{4}+\frac{2}{3}\right)-\left(5-\frac{1}{3}-\frac{6}{5}\right)-\left(6-\frac{7}{4}+\frac{3}{2}\right)\)
e,\(\left(\frac{1}{2}-\frac{13}{14}\right):\frac{5}{7}-\left(\frac{-2}{21}+\frac{1}{7}\right):\frac{5}{7}\)
g,\(\frac{4}{9}:\left(\frac{-1}{7}\right)+6\frac{5}{9}:\left(\frac{-1}{7}\right)\)
Tìm \(n\in\) N*, biết: \(2n\div\left(1+\dfrac{1}{1+2}+\dfrac{1}{1+2+3}+\dfrac{1}{1+2+3+4}+...+\dfrac{1}{1+2+3+4+...+n}\right)=2020\)
Tính nhanh:
a) \(\left(2017^1\right)^{2.4.6.8...2016}\)
b)\(2017^{\left(225-1^2\right).\left(225-2^2\right).\left(225-3^2\right)....\left(225-56^2\right)}\)
