Réponse :
Explications étape par étape
(x = *)
Exercice 1 :
A= a²+ 4a + a² + a - 8
= a² + a² + 4a + a - 8
= 2a² + 5a - 8
B= 17b² + 5b + 9 - 7b² - 3b + 4
= 17b² - 7b² + 5b - 3b + 4
= 10b² + 2b + 4
C= 6c² + 7c - 1 + 5c² - 4c - 8
= 6c² + 5c² + 7c - 4c - 1 - 8
= 11c² + 3c - 9
D= 4d² - 6d + 2 - 7d² + 8d - 10
= 4d² - 7d² - 6d + 8d + 2 - 10
= -3d² + 2d - 8
Exercice 2 :
G= 6(5g - 11)
= 6 x 5g - 6 x 11
= 30g - 66
H= (8h + 9)(h + 10)
= 8h x h + 8h x 10 + 9h + 9 x 10
= 8h² + 80h + 9h + 90
= 8h² + 89h + 90
I= 3i x 11i - 3i x 2 + 7 x 11i - 7 x 2
= 33i² - 6i + 77i - 14
= 33i² - 83i - 14
J= 4(7j + 12)
= 4 x 7j + 4 x 12
= 28j + 48
K= (5k - 1)(6k + 3)
= 5k x 6k + 5k x 3 - 6k - 3
= 30k² + 15k - 6k - 3
= 30k² + 9k - 3
L= (10l - 1)(9l - 8)
= 10l x 9l - 10l x 8 - 9l - 1 x (-8)
= 90l² - 80l - 9l + 8
= 90l² - 89l + 8
Exercice 3 :
M= 9m² + 18
= 9 x m² + 9 x 2
= 9(m² + 2)
N= 4n - 17n²
= n x 4 - n x 17n
=n(4 - 17n)
O= 7o² + o
= o x 7o + o x 1
= o(7o + 1)
P= 6p + 6
= 6 x p + 6 x 1
= 6(p + 1)