а) 54:2=26:2=13:13=1; 65:5=13:13=1; 99:3=33:3=11:11=1; 162:2=81:3=27:3=9:3=3:3=1; 10000:2=5000:2=2500:5=100:5=20:2=5:5=1; 1500:2=750:2=375:3=127:5=25:5=5:5=1; 7000:2=3500:2=1750:2=875:5=175:5=35:5=7:7=1; 3240:2=1620:2=810:2=405:3=135:3=45:3=15:3=7:7=1; 4608:2=2304:2=1152:2=576:2=288:2=14:4=72:2=36:2=18:2=9:2=3:3=1