[ab, ba ] = 162
162=2•3^4
ab divide 162 si ba divide 162
2•3<10 ; (ab≥10)
1. fie ab=2•3^2
ab=18 => ba=81
[18,81]=162
2. ab=3^3
ab=27 => ba=72, nu convine, 72=2^3•3^2
3. ab=2•3^3
ab=54 => ba=45, nu convine, apare si factorul 5; (45=3^2•5)
4. ab=3^4
ab=81 => ba=18
[81,18]=162
=> a=18 si b=81, sau a=81 si b=18
