1. a=numărul
3a-6=x
x:4+10=26
x:4=26-10
x:4=16
x=16×4
x=64
3a-6=64
3a=64+6
3a=70
a=70:3
a=23,33
2. D(12)={1,2,3,4,6,12}
D(18)={1,2,3,6,9,18}
D(21)={1,3,7,21}
D(28)={1,2,4,7,14,28}
D(30)={1,2,3,5,6,10,15,30}
D(32)={1,2,4,8,16,32}
D(40)={1,2,4,5,8,10,20,40}
D(48)={1,2,3,4,6,8,12,16,24,48}