Chung minh rang
1 be hon 1/5+1/6+.....+1/16+1/17 be hon 2
Chứng minh rằng : 1/15 +1/16+1/17 +... +1/43+1/44 > 5/6
chung to rang tong B sau lon hon 1/2 B=1/12+1/13+1/14+1/15+1/16+1/17+1/18+1/19+1/20+1/21+1/22
chung to rang 1/5+1/6+1/7=...+1/16+1/17<2
Chứng minh rằng
\(\frac{1}{15}+\frac{1}{16}+\frac{1}{17}+...+\frac{1}{43}+\frac{1}{44}>\frac{5}{6}\)
Câu1: CMR
1/15+1/16+1/17+....+1/43+1/44>5/6
chung minh rang
1/5+1/14+1/28+1/44+1/61+1/85+1/97<1/2
chung minh rang tong sau khong phai la so tu nhien
1/2+1/3+1/4+1/5+1/6+...+1/16
M=15/15×16+15/16×17+15/17×18+15/18×19+15/19×20
Ko doi ra so thap phan chung to M<1/3