Question

C=\(\frac{1}{1.2}\)+\(\frac{1}{2.3}\)+\(\frac{1}{3.4}\)+....+\(\frac{1}{97.98}\)+\(\frac{1}{98.99}\)

Answer 1

Câu hỏi của lương hiếu - Toán lớp 6 - Học toán với OnlineMath

Làm như link trên nhưng bỏ hạng tử \(\frac{1}{99.100}\)đi

Bước cuối: \(1-\frac{1}{99}=\frac{98}{99}\)

Answer 2

\(C=\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{98.99}\)

\(\Rightarrow C=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{98}-\frac{1}{99}\)

\(\Rightarrow C=1-\frac{1}{99}\)

\(\Rightarrow C=\frac{98}{99}\)

~Study well~

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Answer 3

=1-1/2 +1/2-1/3 +1/3-1/4 +....+1/97.98+1/98+1/99

=1-1/99

 =98/99

Answer 4

 1/97-1/98 nha

Answer 5

\(C=\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{97.98}+\frac{1}{98.99}\)

\(\Rightarrow C=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{97}-\frac{1}{98}+\frac{1}{98}-\frac{1}{99}\)

\(\Rightarrow C=1-\frac{1}{99}\)

\(\Rightarrow C=\frac{98}{99}\)

rất vui vì giúp đc bạn !!!

Answer 6

\(C=\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{97.98}\)

    \(=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{97}-\frac{1}{98}\)

    \(=1-\frac{1}{98}\)

     \(=\frac{98}{98}-\frac{1}{98}\)

     \(=\frac{97}{98}\)

Answer 7

\(C=\frac{1}{1.2} +\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{97.98}+\frac{1}{98.99}\)

\(=\frac{1}{1}-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{97}-\frac{1}{98}+\frac{1}{98}-\frac{1}{99}\)

\(=\frac{1}{1}-\frac{1}{99}\)

\(=\frac{98}{99}\)