a+b+c=69
a=BC=> a=10b+c => 10b+c+b+c=69 => 11b+ 2c=69
ai uitat sa spui ca b,c impare si c>b
cazul 1: c=9 => 11b+18=69 => b= 51/11 nu convine
cazul 2: c=7 => 11b+14=69 => b=55/11=5
=> a=57 , b=5, c=7
