Question

tính 1/2.3+1/3.4+1/4.5+..+1/99.100

Answer 1

1/2*3+1/3*4+...+1/99*100

=1/2-1/3+1/3-1/4+...+1/99-1/100

=50/100-1/100=49/100

Answer 2

\(\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+...+\frac{1}{99.100}=\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{99}-\frac{1}{100}=\frac{1}{2}-\frac{1}{100}=\frac{49}{100}\)

Answer 3

\(\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+...+\frac{1}{99.100}\)\(=>\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+...+\frac{1}{99}-\frac{1}{100}\)

\(=>\frac{1}{2}-\frac{1}{100}=>\frac{50}{100}-\frac{1}{100}=\frac{49}{100}\)