Question

Bài 1: Tìm X : 

1)   2 . X  / 100 = ( 1 - 1/2 ) . ( 1 - 1/3 ) . ( 1 - 1/4 ) . ( 1 - 1/5)

 

Answer 1

\(\frac{2x}{100}=\left(1-\frac{1}{2}\right)\left(1-\frac{1}{3}\right)\left(1-\frac{1}{4}\right)\left(1-\frac{1}{5}\right)\)

\(\frac{2x}{100}=\frac{1}{2}.\frac{2}{3}.\frac{3}{4}\frac{4}{5}\)

\(\frac{2x}{100}=1-\frac{1}{5}\)

\(\frac{2x}{100}=\frac{4}{5}\)

\(\frac{2x}{100}=\frac{80}{100}\)

\(\Rightarrow2x=80\Rightarrow x=40\)

Answer 2

\(2.\frac{x}{100}=\left(1-\frac{1}{2}\right).\left(1-\frac{1}{3}\right).\left(1-\frac{1}{4}\right).\left(1-\frac{1}{5}\right)\)

\(\Leftrightarrow\frac{2x}{100}=\frac{1}{2}.\frac{2}{3}.\frac{3}{4}.\frac{4}{5}\)

\(\Leftrightarrow\frac{x}{50}=\frac{1}{5}\) 

\(\Leftrightarrow x=10\)