Brainly am nevoie de ajutor cu toate exercitiile din poza!

Răspuns:
9a)123,231,601
______
b)28,46,64,82
________
10a)121,212
_________
b) 120120,102102,201201,210210
_________
11a) a+b=3
12,21,30
____________
b) a+2b+c=6
105,204,303,113,212,311,121,220
_________
c) 423,424,425
nr de forma ab=42