Cmr :s3=1/5+1/13+1/25+...+1/10^2+11^2<9/20
Các bạn giúp mình nhé , mk đang cần gấp , bạn nào giải hộ , mk sẽ tick đều đặn. Help me
1.Cmr : A=9/10!+9/11!+9/12!+...+9/1000! < 1/9
2. CHo G = 5/3+8/3^2+11/3^3+...+302/3^100. CMR : 23/9<G<7/2
3.so sánh : L =(1-1/2)(1-1/3)...(1-1/20) với 1/21
4.C=1/101+1/102+...+1/200. CMR:
a/ C>7/12
b//C>5/8
5 cho C = 1/11+1/12+...+1/13+...+1/70
CMR : 4/3<C<2,5
6. Cho B = 4/3+10/9+28/27+...+399/398 . CMR B< 100
So sánh 10^2000+5/10^2001-8 và 10^2000+6/10^2001-7
Tính 1+13^4+13^8+...+13^96+13^100/1+13^2+13^4+...+13^98+13^100+13^102
Tính A=2/5.7+5/7.12+9/19.28+11/28.39+1/39.40
1+2-3-4+5+6-7-8+9+10-11-12+13+98-99-100+101+102
Chứng minh rằng (1/5+1/13+1/25+...+1/10^2+11^2)<9/20
1. -2/9 x 15/17 + -2/9 x 2/17
2. -5/3 x 6/5 + -7/9 x 3/10
3. 15/20 x 7/5 + -9/7 x -6/4
4.-25/13 x 5/19 + -25/13 x 14/19
5 -7/13 x 13/5 + -9/7 x 5/3
6. 27/35 x 5/9 - 2/7 x -7/5
7. 10/13 x 13/5 + {-9/5} x 10/3
8. 100/27 x 9/20 + 40% x 5/3
9. 1,5 x 5/12 + 1/4 x 3/4
10. 2 1/2 x 7/5 + {-9/10} x 2/3
11. X + 45% = 2 1/2 -5/3
12. 80% + X = -5/2 + 3/4
13. 4/25 - X =-5/2 + -3/10
1) 42/35 - [ 33/14 . 21/22 - ( 54/25 : 27/25 - 7/10 )]
2) a) 5/21 . x/34 = 35/102 b) 15/x . 21/13 = 45/91
Ét o ét giúp mình với ạ><!!
CMR: \(\frac{1}{5}+\frac{1}{13}+\frac{1}{25}+...+\frac{1}{1985}<\frac{9}{20}\)
1 + 2 + 3 + 4 + 5 + 6 + 7 +8
3+ 4 +5 + 6 + 7+8 +9 + 10 +11
1+ 3 + 5 + 7 + 9 + 11+ 13 + 15
2+ 4 + 6 + 8 + 10 + 12 + 14 + 16
1+ 4 + 7 + 10 + 13 + 16 + 19 + 22
6+ 8 + 10 + 12 + 14 + 16 + 18
7 + 10 + 13 + 16 + 19 + 22 + 25 / 1 + 5 + 9 + 13 + 17 + 21 + 25 + 29 + 33 + 37