Répondre :
a) 6x+3(x-5)-(x+3) = 4(x-2)
6x+3x-15-x+3 = 4x-8
6x+3x-x-15+3 =4x-8
9x-x-15+3=4x-8
8x-12=4x-8
8x-12-4x=-8
4x=-8+12
4x=4
x=4/4
x=1
b = 3-(4x-7) =(2x+3)-(6x+6)
3 -4x-7 = 2x+ -6x +6
3-4x-7 -2x +6x = 6
-4 +6x =6
6x =6+4
6x =10
x=10-6
x=4