Răspuns:
a) 5^18=(5^2)^9=25^9
3^27=(3^3)^9=27^9
25^9<27^9, deci, 5^18<3^27
b)2^29 si
27^19=(3^3)^19=3^57
2^29<3^57, deci, 2^29<27^19