19/20-(1/4+2/5) 1/30+(3/5-1/6)

спс

19/20-(1/4+2/5)=19/20-(5/20+8/20)=19/20-13/20=6/20=3/101/30+(3/5-1/6)=1/30+(18/30-5/30)=1/30+13/30=14/30=7/15