Có: \(\dfrac{5454}{5757}-\dfrac{171717}{191919}.\dfrac{3}{4}+\dfrac{1}{4}:x=\dfrac{2}{5}\)
=> \(\dfrac{54.101}{57.101}-\dfrac{17.10101}{19.10101}.\dfrac{3}{4}+\dfrac{1}{4}:x=\dfrac{2}{5}\)
=> \(\dfrac{18}{19}-\dfrac{17}{19}.\dfrac{3}{4}+\dfrac{1}{4}:x=\dfrac{2}{5}\)
=> \(\dfrac{21}{76}+\dfrac{1}{4}:x=\dfrac{2}{5}\)
=> \(\dfrac{1}{4}:x=\dfrac{47}{380}\)
=> x = \(\dfrac{95}{47}\)
=>18/19-17/19*3/4+1/4:x=2/5
=>1/4:x=2/5-18/19+17/19*3/4=47/380
=>x=1/4:47/380=95/47