№1
а)
1/4=2/8(2), 3/12(3), 4/16(4),5/20(5)
б)
1/5=2/10(2),3/15(3),4/20(4),20/100(20)
№2
а)1/2=3/6,9/18,12/24,15/30
б)5/6=10/12,20/24,40/48,100/120
в)2/3=6/9,14/21,24/36,100/150
г)4/7=8/14,16/28,36/63,80/140
№3
а)6/24,28/24,9/24,34/24
б)60/90,126/90,40/90,96/90
в)15/36,28/36,30/36,36/36=1ц.
г)60/100,75/100,32/100,14/100