Bonjour,
Exercice 2 :
a. 2a-3 = -5a+11
Pour a = 2
2×2-3 = -5×2+11
4-3 = 10+11
1 = 1. Vrai
b. 4b-2 = -b+1
Pour b = -1
4×(-1)-2 = -(-1)+1
-4-2 = 1+1
-6 = 2. Faux
c. 3c(2c-5) = d²+2
3×(-5)×(2×(-5)-5) = (-2)²+2
3×(-5)×(-10-5) = 4+2
3×(-5)×(-15) = 6
225 = 6. Faux
