3/4*4/5:9/10=3*4/4*5 * 10/9 = 3*10/5*9=2/3
6/7:3/5*1 2/5=6/7*5/3 * 7/5 = 6*5*7/7*3*5=2
3/8*4/5:9/10=3*4/8*5 * 10/9 = 3/10 * 10/9 = 3*10/10*9=1/3
11/23 * 3 2/7 :5 1/2 = 11/23 * 23/7 : 11/2 = 11*23/23*7 * 2/11=11/7*2/11=11*2/7*11 = 2/7
3/5*(2 2/3 : 3 1/5)=3/5*8/3:16/5=3*8/5*3 * 5/16 = 8/5*5/16=8*5/5*16=1/2
1 1/8*(9 1/3:1 3/4)=9/8*28/3:7/4=9*28/8*3 * 4/7=3*7/2*3 * 4/7=3*7*4/2*3*7=2