a) [tex] \frac{5 ^{21} }{5 ^{23} } [/tex] simplificam prin 5²¹ obtinem [tex] \frac{1}{5^{2} } = \frac{1}{25} [/tex]
b) [tex] \frac{9^{17} }{27 ^{12} } [/tex] =[tex] \frac{9^{17} }{9^{24} } [/tex] simplificam prin 9¹⁷ obtinem [tex] \frac{1}{9^{7} } [/tex]