Tính tổng : B = 12 + 22 + 32 + ... + 992 + 1002
C = 1012 + 1022 + ... + 1992 + 2002
D = 1.3 + 2.4 + 3.5 + 4.6 + ... + 99.100 +1010.102
T = 1.100 + 2.99 + 3.98 + ... + 99.2 + 100.1
S = 1.2.3 + 2.3.4 + 3.4.5 + ... + 98.99.100
Giúp mk nha các bạn!
C = 1 x 2 + 3 x 4 + ... + 99 x 100
D = 21 + 22 + 23 + 24 + ... + 299 + 2100
1. 1+ (-2) + 3+ (-4) + . . . +19 + (-20)
2. 1 - 2 + 3- 4 + . . . + 99 - 100
3. -1 + 3 -5 + 7 - . . . +97 - 99
4. 1+ 2 - 3+ 4 + . . . +97 + 98 - 99 - 100
tính giá trị biểu thức sau
A= -1 -2 +3 +4 -5 -6 +7 +8-9-10+11+12 -...........-2013-2014+2015+2016
B= [\(\dfrac{1}{2}\) -1 ] : [\(\dfrac{1}{3}\) -1] : ...................: [\(\dfrac{1}{99}\) -1} : [\(\dfrac{1}{100}\) -1]
a ) A = 1/4 + 1/4^2 +1/4^3 +.........+ 1/4^100 + 1/3.4^100
b) B = 1/3 - 1/3^2 + 1/3^3 - 1/3^4 +.........+ 1/ 3^99
CMR: 100- \(\left(1+\dfrac{1}{2}+\dfrac{1}{3}+...+\dfrac{1}{100}\right)=\dfrac{1}{2}+\dfrac{2}{3}+\dfrac{3}{4}+...+\dfrac{99}{100}\)
CMR 100-(1+\(\dfrac{1}{2}+\dfrac{1}{3}+...+\dfrac{1}{100}\))= (\(\dfrac{1}{2}+\dfrac{2}{3}+\dfrac{3}{4}+...+\dfrac{99}{100}\))
CMR:1/3-2/3^2+3/3^3-4/3^4+.......+99/3^99-100/3^100<3/16
Tính giá trị của phân số sau:
\(\dfrac{101+100+99+...+3+2+1}{101-100+99-98+...+3-2+1}\)