Bonsoir,
Petit rappel à connaître par ♡ :
• (a+b)² = a²+2ab+b²
• (a-b)² = a²-2ab+b²
• (a+b)(a-b) = a²-b²
Factoriser :
A = 3(x-10)(x+10)+(2x+5)(x+10)
A = (x+10)(3(x-10)+2x+5)
A = (x+10)(3x-30+2x+5)
A = (x+10)(5x-30+5)
A = (x+10)(5x-25)
A = (x+10)×5(x-5)
A = 5(x+10)(x-5)
B = (5x-9)²+(5x+10)(5x-9)
B = (5x-9)(5x-9+5x+10)
B = (5x-9)(10x-9+10)
B = (5x-9)(10x+1)
C = (3x+4)²-25
C = (3x+4-5)(3x+4+5)
C = (3x-1)(3x+4+5)
C = (3x-1)(3x+9)
C = (3x-1)×3(x+3)
C = 3(3x-1)(x+3)
Bonne soirée.
