Réponse :
Bonsoir
Explications étape par étape :
A= (x^7)^2/x^15
A = x^14 / x^15
A = x^(14-15)
A = x^-1
B=x^-5*x^3/x^-12
B = x^-2 / x^-12
B = x^(-2-(-12))
B = x^(-2+12)
B = x^10
C =x*x^3/x^2
C = x^4 / x^2
C = x^(4-2)
C = x^2
D = - 1/x^-7*x^3
D = -1 / x^-4
D = -x^4