Réponse :

a) 7x+13=10x-2

7x - 10x = -13 - 2

-3x = -15

x= -15/-3

x= 5

S= {5}

b) 12-15x=23-(3x+12+11x)

12-15x=23-(14x+12)

12-15x=23-14x-12

-15x+14x= -12-12+23

-x= -1

x=1

S= {1}

c) 2(3x+5)=6x-5​

6x+10=6x-5

6x-6x=-10-5

0x=-15

S= pas de solution