Bonjour,

1) (a - b)² = a² - 2ab + b²

a = (a - 8)²

a = a * a - a * 8 * 2 - 8 * - 8

a = a² - 16a + 64

b = (1 - 4y)²

b = 1 * 1 - 4y * 1 * 2 - 4y * - 4y

b = 1 - 8y + 16y²

c = (7 - 2t)²

c = 7 * 7 - 7 * - 2t * 2 - 2t * - 2t

c = 49 - 28t + 4t²

2) (a + b) (a - b) = a²- b²

D = (d + 8) (d - 8)

D = d * d + 8 * - 8

D = d² - 64

E = (3a - 1) (3a + 1)

E = 3a * 3a - 1 * 1

E = 9a² - 1

F = (5 + 7b) (5 - 7b)

F = 5 * 5 + 7b * - 7b

F = 25 - 49b²

3) (a + b)² = a² + 2ab + b²

G = (9 + y)²

G = 9 * 9 + 9 * y * 2 + y * y

G = 81 + 18y + y²

H = (6t + 1)²

H = 6t * 6t + 6t * 1 * 2 + 1 * 1

H = 36t² + 12t + 1

J = (5a + 3)²

J = 5a * 5a + 5a * 3 * 2 + 3 * 3

J = 25a² + 30a + 9.

Réponse :

Bonjour

Explications étape par étape

Partie 2

A = (a -8)² = a² +64 -16a

B = (1 -4y)² = 1 -8y +16y²

C = (7 -2t)² = 49 -28t +4t²

Exercice 2

D = (d +8) (d-8) = d² -64

E = (3a -1)(3a +1) = 9a² -1

F = (5 +7b)(5 -7b) = 25 -49b²

Exercice 3

G = ( 9+y)² = 81 +18y +y²

H = (6t +1)² = 36t² +12t +1

J = (5a +3)² = 25a² +30a +9