Cho B=1/61+1/62+1/63+.....+1/80.Chứng minh B<1/2
Chứng minh: A= 1/3+1/13+1/14+1/15+1/61+1/62+1/63+1/64+1/65+1/66<3/4
chứng minh rằng s=1/5+1/13+1/14+1/15+1/61+1/62+1/63<1/2
CHO 1/5+1/13+1/14+1/15+1/61+1/62+1/63
cHỨNG minh 3/7<S<1/2
chứng minh rằng: S=1/5+1/13+1`/14+1/15+1/61+1/62+1/63<1/2
1, Tính :
a, A = 1.(-1)+3.(-1)^2+5.(-1)^3.7+(-1)^4+9.(-1)^5
b, 1-2-3+4+5-6-7+8+...+61-62-63-64
1, Tính :
a, A = 1.(-1)+3.(-1)^2+5.(-1)^3.7+(-1)^4+9.(-1)^5
b, 1-2-3+4+5-6-7+8+...+61-62-63-64
Chứng minh rằng ; S = 1/5+1/13+1/14+1/15+1/61+1/62+1/63 < 1/2
ai nhanh nhất mình sẽ tick cho đấy
Chứng minh:S=1/3+1/13+1/14+1/15+1/61+1/62+1/63+1/64+1/65+1/66<3/4
