14/7<m/56<3/8
14/7<m/56 7m<56*14 m<784/7 m<112
m/56<3/8 8m<56*3 m<168/8 m<21 112>m<21
2/5<m/30<1/2
2/5<m/30 5m<30*2 m<60:5 m<12
m/30<1/2 2m<30*1 m<30;2 m<15 12>m<15
1/2<(n+2)/4<5/3
1/2<(n+2)/4 2(n+2)<4*1 2n+4<4 n<4-4:2 ,n=0
(n+2)/4<5/3 3(n+2)<4*5 3n+6<20 n<14/3 n<4,66
