C/minh:
1-1/2+1/3-1/4+...+1/99-1/100=1/101+1/102+...+1/200
Tính các tổng sau:
a) A = 1*2+2*3+3*4+...+2014*2015
b) B = 101^2+102^2+...+199^2+200^2
c) C = 1*3+2*4+3*5+4*6+...+99*101+100*102
1.Chưng minh rằng (1+/1/3+1/5+....+1/99)-(1/2+1/4+1/6+...+1/100)=1/51+1/52+...+1/100
2.Áp dụng phan 1 để chung minh 1-1/2+1/3-1/4+.....-1/200=1/101+1/102+.......+1/200
CMR : ( 1 + 1/3 + 1/5 + ...+ 1/99 ) + ( 1/2 + 1/4+ ..1/200 ) = 1/101 + 1/102+..+1/200
câu 1 : tính tổng
A = 1+(-3) +5+ (-7) + ...+ 17 + (-19 )
C = 1+2-3-4+5+6 -7-8 +...-99-200+101+102
B = 1-4+7-10+...-100+103
bai 1: tính tổng
1, 1+2+3+.....+99+100
2, 101+102+103+......+200+201
3, 2+5+8+11+......+294+206
4, 11+22+33+44+..........+99+110
5, 367+361+155+........+7+1
CMR:
a, \(100-\left(1+\frac{1}{2}+\frac{1}{3}+..+\frac{1}{100}\right)=\frac{1}{2}+\frac{2}{3}+\frac{3}{4}+..+\frac{99}{100}\)
b, \(\left(1+\frac{1}{3}+\frac{1}{5}+...+\frac{1}{199}\right)-\left(\frac{1}{2}+\frac{1}{4}+..+\frac{1}{200}\right)=\frac{1}{101}+\frac{1}{102}+...+\frac{1}{200}\)
Giải nhanh giùm mình nhé!!!!!!!!!!!!!!
bài 1
A=1*2*3+2*3*4+3*4*5+...+99*100*101
B=1*3*5+3*5*7+...+95*97*99
C=2*4+4*6+..+98*100
D=1*2+3*4+5*6+...+99*100
E=1^2+2^2+3^2+...+100^2
G=1*3+2*4+3*5+4*6+...+99*101+100*102
H=1*2^2+2*3^2+3*4^2+...+99*100^2
I=1*2*3+3*4*5+5*6*7+7*8*9+...+98*99*100
K=1^2+3^2+5^2+...+99^2
Hôm nào cô cũng cho bài khó TTvTT
BT1 :
Cho C = \(\frac{1}{101}+\frac{1}{102}+...+\frac{1}{200}\)
Chứng tỏ rằng \(\frac{1}{2}< C< 1\)
BT2 :
Cho D = \(\frac{1}{101}+\frac{1}{102}+...+\frac{1}{150}\)
Chứng tỏ rằng \(\frac{1}{3}< D< \frac{1}{2}\)
BT3 : Tính :
G = 1 + 22 + 32 + 42 +...+ 1002
H = 12 + 32 + 52+...+992
I = 1 . 2 . 3 + 3 . 4 . 5 + 5 . 6 . 7+ 99 . 100 . 101