`51/57=(3.17)/(3.19)=17/19`
`1717/1919=(101.17)/(101.19)=17/19`
`171717/191919=(10101.17)/(10101.19)=17/19`
`=>51/57=1717/1919=171717/191919`
Ta có
\(\dfrac{51}{57}=\dfrac{17}{19}\)
\(\dfrac{1717}{1919}=\dfrac{17}{19}\)
\(\dfrac{171717}{191919}=\dfrac{17}{19}\)
Mà
\(\dfrac{17}{19}=\dfrac{17}{19}=\dfrac{17}{19}\)
Nên
\(\dfrac{51}{57}=\dfrac{1717}{1919}=\dfrac{171717}{191919}\)