.............................=
1) 13,25 - 2 5/27=13 1/4 - 2 5/27=13 27/108 - 2 20/108=11 7/108
2) 11 7/108 - 10 5/6=11 7/108 - 10 90/108=25/108
3) 25/108 *230,04=25/108 * 23004/100=213/4=53 1/4
4) 1 3/7+3 1/3=1 9/21+3 7/21=4 16/21
5) 12 1/3 - 14 2/7=12 7/21 - 14 6/21= - 1 20/21
6) 4,675 : 4 16/21 =187/40 * 21/100=3927/4000
7) 3927/4000 : ( -1 20/21)= - 3927/4000 * 21/41= -