Sagot :
Réponse :
Bonjour,
A = 70a - 21
= 7 * 10 * a - 7 * 3
= 7(10a - 3)
B = 9x² - 3x + 6
= 3 * 3 * x² - 3 * x + 3 * 2
= 3(3x² - x + 2)
C = 18b⁴ - 18b²
= 18 * b² * b² - 18 * b²
= 18b²(b² - 1)
Identité remarquable (a + b)(a - b) ⇔ a² - b²
D = (3x - 2)² - 16²
= [(3x - 2) + 16][(3x - 2) - 16]
= (3x - 2 + 16)(3x - 2 - 16)
= (3x + 14)(3x - 18)
= (3x + 14) * 3(x - 6)
= 3(3x + 14)(x - 6)
Bonsoir,
[tex]A = 70a - 21 = 7 \cdot 10 \cdot a - 7\cdot 3 = 7(10a - 3)[/tex]
[tex]B = 9x^2 - 3x + 6 = 3\cdot3\cdot x^2 - 3\cdot x + 3\cdot 2 = 3(3x^2 - x + 2)[/tex]
[tex]C = 18b^4 - 18b^2 = 18b^2(b^2 - 1)[/tex]
[tex]D = (3x - 2)^2 - 16^2 = (3x - 2 + 16)(3x - 2 - 16) = (3x + 14)(3x - 18) \\\\D = (3x + 14)(3x - 3\cdot 6) = 3(3x + 14)(x - 6)[/tex]
Bonne soirée,
Thomas