bonjour
1)
P= (6x-4) (2x+5) -(3x+2) (2x+5)
= (2x+5) [ 6x-4 -3x-2)]
=(2x+5) (3x-6)
=3(2x+5)(x-2)
2)
on se sert de l’identité remarquable
a²-b² = (a-b)(a+b)
Y= (4x-5)² -(9-13x)²
Y=[4x-5-9+13x][4x-5 +9-13x]
Y= (17x -14) (4-9x)
3)
T= 25x²+9 -30x
on utilise l'identité remarquable (a-b)²
(a-b)² = a²-2ab +b²
a = 5x
b = 3
T= (5x-3)²= 5²x² -2×5×3 ×x + 3²= 25x² -30x +9
T= (5x-3)²
4)
H= (3x-2)[ (5x-7 -x+8)]
H= (3x-2) (4x+1)