Question

A = \(\frac{8}{9}.\frac{15}{16}.\frac{24}{25}....\frac{2499}{2500}\)tính A

. là nhân nha

Answer 1

\(\frac{8}{9}\cdot\frac{15}{16}\cdot\cdot\cdot\cdot\cdot\frac{2499}{2500}\)

=\(\frac{2\cdot4}{3\cdot3}\cdot\frac{3\cdot5}{4\cdot4}\cdot\cdot\cdot\cdot\cdot\frac{49\cdot51}{50\cdot50}\)

=rút gọi tử và mẫu

=\(\frac{2}{3}\cdot\frac{50}{51}\)

=\(\frac{100}{153}\)

Answer 2

A = 89 .1516 .2425 ....24992500 

 \(A=\frac{2.4}{3.3}.\frac{3.5}{4.4}.\frac{4.6}{5.5}.....\frac{49.51}{50.50}\)

\(A=\frac{2.3.4.....49}{3.4.5.....50}.\frac{4.5.6.....51}{3.4.5....50}\)

\(A=\frac{2}{50}.\frac{51}{3}\)

\(A=\frac{17}{25}\)

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