Question

so sánh \(M=\frac{1}{1.2}+\frac{1}{2.3}+...+\frac{1}{49.50}\) với 1

nhanh nhanh đúng mình tik cho

Answer 1

\(M=\frac{1}{1.2}+\frac{1}{2.3}+...+\frac{1}{49.50}\)

\(M=\frac{1}{1}-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{49}-\frac{1}{50}\)

\(M=\frac{1}{1}-\frac{1}{50}=\frac{49}{50}\)

Vì \(\frac{49}{50}\)< 1 nên M < 1.

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#Sunrise

Answer 2

\(M=\frac{1}{1.2}+\frac{1}{2.3}+...+\frac{1}{49.50}\)

\(M=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{49}-\frac{1}{50}\)

\(M=1-\frac{1}{50}\)

\(M=\frac{50}{50}-\frac{1}{50}\)

\(M=\frac{49}{50}\)\(< \frac{50}{50}\)

\(M< 1\)

Chúc bạn học tốt nha !!! 

Answer 3

M=\(\frac{1}{1.2}+\frac{1}{2.3}+.....+\frac{1}{49.50}\)

=\(\frac{1}{1}-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+.....+\frac{1}{49}-\frac{1}{50}\)

= \(\frac{1}{1}-\frac{1}{50}=\frac{49}{50}\)

\(\frac{49}{50}< 1\)