CMR:\(\frac{1}{5}+\frac{1}{15}+\frac{1}{25}+...+\frac{1}{1985}< \frac{9}{20}\)
CMR:
\(\frac{1}{5}+\frac{1}{15}+\frac{1}{25}+...+\frac{1}{1985}< \frac{9}{20}\)
CMR \(A=\frac{1}{5}+\frac{1}{15}+\frac{1}{25}+...+\frac{1}{1985}< \frac{9}{20}\)
Cho : A= \(\frac{1}{5}+\frac{1}{15}+\frac{1}{25}+...+\frac{1}{1985}\)
CMR: A<\(\frac{9}{20}\)
CMR \(\frac{1}{5}+\frac{1}{15}+\frac{1}{25}+...+\frac{1}{1985}<\frac{9}{20}\)
Cho xin lời giải nhá mọi người
Chứng minh rằng \(\frac{1}{5}+\frac{1}{15}+\frac{1}{25}+...+\frac{1}{1985}< \frac{9}{20}\)
Chứng minh rằng:
\(\frac{1}{5}+\frac{1}{15}+\frac{1}{25}+..........+\frac{1}{1985}< \frac{9}{20}\)
Chứng minh:\(A=\frac{1}{5}+\frac{1}{15}+\frac{1}{25}+...+\frac{1}{1985}< \frac{9}{20}\)
Chứng minh: \(\frac{1}{5}+\frac{1}{15}+\frac{1}{25}+...+\frac{1}{1985}<\frac{9}{20}\)
