Sagot :
A = (x+10)(x-10) identité remarquable
B = (7x+5)² idem
C = (x+1-3)(x+1+3) idem
x² - 100 = (x - 10)(x + 10)
49x² - 70x +25 = (7x -5)²
(x+1)² - 9 = (x+1-3)(x+1+3) =(x-2)(x+4)
Qui peut m'aidez ? Factorise A = x²-100 B = 49x²-70x + 25 C = (x+1)² -9
A = (x+10)(x-10) identité remarquable
B = (7x+5)² idem
C = (x+1-3)(x+1+3) idem
x² - 100 = (x - 10)(x + 10)
49x² - 70x +25 = (7x -5)²
(x+1)² - 9 = (x+1-3)(x+1+3) =(x-2)(x+4)