2*3/8+1*5/6=3/4+5/6=9/12+10/12=
19/12=1 7/12
4*3/8+8*1/2=3/2+4=1 1/2+4=5 1/2
4*2/5+9*3/7=8/5+27/7=1 3/5+3 6/7=
1 21/35+3 30/35=4 51/35=5 16/35
