Aide Factorisation Bonjour j'ai un dm pour demain et je n'arrive pas a factoriser les expressions g(x) et l(x) de l'exercice 23 et je bloque sur la totalité de

exo 23 : 

g(x) = (2x-5)(x+6) - 2x - 12
g(x) = (2x-5)(x+6) - 2(x+6)
g(x) = (x+6)(2x-5-2)
g(x) = (x+6)(2x-7)

l(x) = 4x² - 1 - (3x+5)(2x-1)
l(x) = (2x)² - 1² - (3x+5)(2x-1)
l(x) = (2x-1)(2x+1) - (3x+5)(2x-1)
l(x) = (2x-1)(2x+1-3x-5)
l(x) = (2x-1)(-x-4)

exo 24 :

a(x) = (x-1)(2x-3) - (1-x)² + x - 1
a(x) = (x-1)(2x-3) - (x-1)(x-1) + 1(x-1)
a(x) = (x-1)(2x-3-x+1+1)
a(x) = (x-1)(x-1)
a(x) = (x-1)²

b(x)  = (2x+3)(x-1) + (x+1)(4-5x)
b(x) = 2x² + x - 3 + -x + 4 -5x²
b(x) = -3x² + 1 
ceci n'est pas factorisable ... erreur ? 

c(x) = (x-3)(x+2) + (x+2)² + 2x² + 4x
c(x) = (x-3)(x+2) + (x+2)(x+2) + 2x(x+2)
c(x) = (x+2)(x-3 + x + 2 + 2x)
c(x) = (x+2)(4x-1)

d(x) = (x+3)(x+1) - (x-3)(x-1)
d(x) = x² + 4x + 3 - (x² - 4x + 3)
d(x) = x² + 4x + 3 - x² + 4x - 3
d(x) = 8x

e(x) =2(4x-5)² - 5x(5-4x)
e(x) = 2(5 - 4x)^2 - 5x(5-4x)
e(x) = (5 - 4x)( 2(5-4x) - 5x)
e(x) = (5-4x)(-13x + 10)

f(x) = (6x-3)(x+1) - (2x-1)(x+1) + (1-2x)²
f(x) = 6x² + 3x - 3 -(2x-1)(x+1) + 4x² - 4x + 1
f(x) = 3 (2x-1)(x+1) - (2x-1)(x+1) + (2x-1)²
f(x)  = (2x-1)( 3(x+1) - x - 1 + 2x - 1)
f(x) = (2x-1)( 3x + 3 - x - 1 + 2x - 1)
f(x) =  (2x-1)(4x+1)