Calculați folosind regulile de calcul cu puteri

Răspuns:
a) [(3/7)⁸]⁵:(3/7)¹⁷=(3/7)^(40-17)=(3/7)²³
b) [(5/9)⁴]⁶:(5/9)¹¹=(5/9)^(24-11)=(5/9)¹³
c) (2/5)⁵¹:[(2/5)⁷]³=2/5^(51-21)=(2/5)³⁰