Bonsoir,
Factoriser:
C = 5x² + 15x
C = 5x*x² + 5x*3
C = 5x(x² + 3)
D = (2x - 3)² - (1 - x)(2x - 3)
D = (2x - 3)(2x - 3) - (1 - x)(2x - 3)
D = (2x - 3)(2x - 3 - (1 - x))
D = (2x - 3)(2x - 3 - 1 + x)
D = (2x - 3)(3x - 4)
E = x² - 14x + 49 <=> x² - 2*x*7 + 7²
→ identité remarquable :
E = (x - 7)²
F = (3x + 5)² - (x - 8)²
→ identité remarquable :
F = (3x + 5 - (x - 8))(3x + 5 + (x - 8))
F = (3x + 5 - x + 8)(3x + 5 + x - 8)
F = (2x + 13)(4x - 3)
* = multiplication
Bonne soirée.
