Question

Rút gọn 

B = (1 - 1/2 ) . ( 1 - 1/3 ) . ( 1.1/4 ) ... ( 1 - 1/20 )

giúp mik vs 

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Answer 1

\(B=\left(1-\frac{1}{2}\right).\left(1-\frac{1}{3}\right).\left(1-\frac{1}{4}\right)...\left(1-\frac{1}{20}\right)\)

\(B=\frac{1}{2}.\frac{2}{3}.\frac{3}{4}...\frac{19}{20}\)

\(B=\frac{1.2.3...19}{2.3.4...20}\)

\(B=\frac{1}{20}\)

Answer 2

B=(1-1/2)(1-1/3)........(1-1/20)

B=1/2.2/3.......19/20

B=1/20

Answer 3

B = \(\frac{1}{2}.\frac{2}{3}.\frac{3}{4}...\frac{19}{20}\)

B=  \(\frac{1.2.3...19}{2.3.4...20}\)

B=   \(\frac{1}{20}\)