Aidez-moi s’il vous plaît pour l’exercice 1et2

Réponse:

exo1

a) -2a+8=0

-2a=-8

a= 8/2

a= 4

b) 3x = 7/4

x= 7/4×3

x= 7/12

c) -5x+12=-3

-5x=-12-3

-5x=-15

x= -15/3

x=-5

Bonjour,

Exercice 1

-2a = -8

a = -8/-2 =  4

3x= 7/4

x= (7/4)/3

x = 7/4 * 1/3

x= 7/12

-5x +12 =-3

-5x = -3-12

-5x = -15

x = -15/-5

x= 3

Exercice 2

3a+7 = 3*-1  +7 = -3 +7 = +4

-9+2a = -9  + 2*-1 = -9 -2= -7

4 ≠ -7

donc, non

-3m+3 = -3* -1/2  +3 = 3/2 +3 = 9/6 + 9/6 =  18/6 = 3

2-5m = 2  -5*-1/2 = 2 +5/2  = 4/2 +5/2 = 9/2 = 4,5

3 ≠ 4,5

donc, non