Question

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

Answer 1

M\(=\frac{1}{1.2}+\frac{1}{2.3}+...+\frac{1}{49.50}=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{49}-\frac{1}{50}\)

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

Answer 2

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

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

vì \(\frac{49}{50}

Answer 3

=>M=1/1-1/2+1/2-1/3+....+1/49-1/50
=>M=1/1-1/50
=>M=0.98

Answer 4

m=1-1/2+1/2-1/3+1/3-1/4+.......+1/49-1/50

m=1-1/50

M<1

Answer 5

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

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

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

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

Answer 6

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

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

            \(=1-\frac{1}{50}\)

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

             \(=\frac{49}{50}< 1\)

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

Chúc bạn  học tốt !!!