abc=100a+10b+c
cba=100c+10b+a
100a+10b+c= 3(100c+10b+a)+a+b+c
100a+10b = 300c+30b+3a+a+b
96a=300c+21b
a,b,c pot fi 1-9 (rezolvam prin înercari)
a = 8, c=2, b=8
96·8=300·2+21·8
768 = 600+168
a=8, b=8, c=2
abc=882, cba=288
V: 3·288+8+8+2=864+18=882=abc