Sagot :
Bonjour,
(x - 1)(x + 2) = x * x + x * 2 - 1 * x - 1 * 2 = x² + 2x - x - 2= x² + x - 2
(x - 3)(x + 5) = x * x + x * 5 - 3 * x - 3 * 5 = x² + 5x - 3x - 15 = x² + 2x - 15
(x - 6)(2x - 3) = x * 2x + x * -3 - 6 * 2x - 6 * -3 = ......
Bonjour,
A= (x-1)(x+2)
A=x*x+2*x-1*x-1*2
A=x^2+2x-x-2
A=x^2+x-2
B=(x-3)(x+5)
B=x*x+5*x-3*x-3*5
B=x^2+5x-3x-15
B=x^2+2x-15
C= (x-6)(2x-3)
C=2x*x-3*x-6*2x-6*-3
C=2x^2-3x-12x+18
C=2x^2-15x+18
Bonne journée.