Coucou,
*=multiplié
Tu sais que :
(a - b)² = a² - 2*a*b + b² = a² - 2ab + b²
(a + b)²= a² + 2*a*b + b² = a² + 2ab + b²
Maintenant, on applique la formule :
A = (6 + x)² = 6² + 2*6*x + x² = 36 + 12x + x² = x² + 12x + 36
B = (6 - x )² = 6² - 2*6*x + x² = 36 - 12x + x² = x² - 12x +36
C = (6 x X )² = 6² x X² = 36 x X² = 36 X²
D = (3 + x )² = 3² + 2*3*x + x² = 9 + 6x + x² = x²+ 6x + 9
E = (3 - x )² = 3² - 2*3*x + x² = ....(je pense que tu as compris, je te laisse finir)
F = (3 x X ) ²= 3² x X² = 9 X²
Voilà :)
