Cho S= 1/31 + 1/32 + 1/33 +....+ 1/59 + 1/60. CMR 3/5<S<4/5
Cho S=1/31+1/32+1/33+.........+1/60. CMR:3/5<S<4/5
Cho S= 1/31+1/32+1/33+...+1/60
CMR:3/5<S<4/5
cho s=1/31+1/32+1/33+..+1/60
cmr:3/5<s<4/5
cho S=1/31+1/32+1/33+...+1/60 Cmr S<4/5
Cho S = 1/31+1/32+1/33+.......+1/60.Chứng minh 3/5 < S < 4/
cho S=1/31+1/32+1/33+...+1/60 chung minh 3/5 < S < 4/5
cho S = 1/31+1/32+1/33+.......+1/60. Chứng minh rằng 3/5 < S< 4/5 .
Cho S=1/31+1/32+1/33+...+1/60. Chứng minh rằng:3/5<S<4/5