Question

упростите выражение (11/12)*(12/11)*(13/14)*(14/13)*(15/14)*(14/15)*(17/16)*(16/17)*(19/18)*(18/19).

Answer 1

$\underbrace {\frac{11}{12}\cdot \frac{12}{11}}_{1}\cdot \underbrace {\frac{13}{14}\cdot \frac{14}{13}}_{1}\cdot \underbrace {\frac{15}{14}\cdot \frac{14}{15}}_{1}\cdot \underbrace {\frac{17}{16}\cdot \frac{16}{17}}_{1}\cdot \underbrace {\frac{19}{18}\cdot \frac{18}{19}}_{1}= 1$