Réponse :

Bonjour

Explications étape par étape

Exercice 1

P(A) = 2/5 = 40%

P(B) = 13/20 = 65 %

P(C) = 55/125 = 44 %

Exercice 2

25% = 1/4

40% = 4/10

Exercice 3

4 n -1 = 7

4n = +1 +7

4n = 8

n = 8/4 = 2

7 -2a = 1

-2a = -7 +1

-2a = -6

a = -6/-2 = +3

-2(x -3) = 0

-2x +6 = 0

-2x = -6

x = +6/2 = +