Réponse :

Bonjour

Explications étape par étape

A = 27 * 9^5

A = 3^3 * 3^5 * 3^5

A = 3^(3+5+5)

A = 3^13

B = 81^4 * 9^-2/27^-3

B = 3^4*3^4*3^4*3^4*3^-2*3^-2/3^-3*3^-3*3^-3

B = 3^(16-4)/3^-9

B = 3^12/3^-9

B= 3^((12-(-9))

B = 3^(12+9)

B = 3^21

C =9^-3*81^2

C = 3^-2*3^-3*3^2*3^2*3^2*3^2

C = 3^-6*3^8

C = 3^(-6+8)

C = 3^2