10,9-2,16/19*(2,27+9,792:6,4)+(5,11/14-4,20/21):3,11/63=
1)9,792:6,4=1,53 2)2,27+1,53=3,3 3)5/6 4)9 5/9 5)21/80 6)1 31/90 7)1 437/720