Bonjour,
L = 4x²-(x+3)(x-2)+2(x-2) = 4x²-(x²-2x+3x-6)+2x-4
= 4x²-x²+2x-3x+2x+6-4
= 3x²+x+2
si x=-5, L = 3(-5)²+(-5)+2 = 75-5+2 = 72
si x=1/2, L = 3(1/2)²+1/2+2 = 3/4+1/2+2 = 5/4+2 = 13/4