Explications étape par étape:
Exercice 1:
A = (x+4) (x+3)
A = x²+3x+4x+12
A = x²+7x+12
B = (y + 3) (2y + 8)
B = 2y²+8y+6y+24
B = 2y²+14y+24
C = (3z + 4) (562)
C = 1686z+2248
D = (-7t+8)(3 - 5t)
D = -21t+35t²+24-40t
D = 35t²-61t+24
E = (7 + 3x) (9x - 3)
E = 63x-21+27x²-9x
E = 27x²+54x-21
F = (-2-3y) (4 - 8y)
F = -8+16y-12y+24y²
F = 24y²+4y-8
G = (4a + 6) (-3-5a)
G = -12a+20a²-18-30a
G = 20a²-42a-18
H = (5z - 7) (8z + 2)
H = 40z²+10z-56z-14
H = 40z²-46z-14