Salut !
D = 9+3(x+5) = 9+3x+15 = 3x+24
F = 14x-5(2x-3) = 14x-10x+15 = 4x+15
si x=3
G = 2x²-5x+6 = 2(3²)-5(2)+6 = 18-10+6 = 14
H = (2x-3)(3-2x) = (2(3)-3)(3-2(3)) = (6-3)(3-6) = 3(-3) = -9
I = 7x-(4-6x) = 7x-4+6x = 13x-4
J = 4x²+(-3+2x)-(x²-4x+7) = 4x²-3+2x-x²+4x-7 = 3x²+6x-10
