4/5÷8; 3/7÷12; 21÷7/8; 8÷16/21; 1/8÷3/4; 1/2÷9; 2/5÷7; 3/4÷9/16

4/5:8=4/5*1/8=1/103/7:12=3/7*1/12=1/2821:7/8=21*8/7=248:16/21=8*21/16=21/2=10 1/2=10,51/8:3/4=1/8*4/3=1/61/2:9=1/2*1/9=1/182/5:7=2/5*1/7=2/353/4:9/16=3/4*16/9=4/3=1 1/3