bonjour possible de m’aider sur sa Exercice n°7 : Développer et réduire les expressions suivantes.
A = (x + 5)(x + 1)
D= (x + 3)(y + 2)
B = (x+3)(2x + 5)
E = (3 - 2x)(4 - x)
C = (x - 4)(x+6)
F= 2x(1 - x) - (x - 3)(3x + 2)


Sagot :

A=(X+5)(X+1)

=(X×X)+(X×1)+(5×X)+(5×1)

=X^2+X+5X+5

=X^2+6X+5

B=(X+3)(Y+2)

=(X×Y)+(X×2)+(3×Y)+(3×2)

=XY+2X+3Y+6

C=(X+3)(2X+5)

=(X×2X)+(X×5)+(3×2X)+(3×5)

=2X^2+5X+6X+15

=2X^2 +11X+15

D=(3-2X)(4-X)

=(3×4)-(3×X)-(2X×4)+(2X×X)

=12-3X-8X+2X^2

=2X^2-11X+12

E=(X-4)(X+6)

=(X×X)+(X×6)-(4×X)-(4×6)

=X^2+6X-4X-24

=X^2+2X-24

F=2X(1-X)-(X-3)(3X+2)

=(2X×1)-(2X×X)- (X×3X) -(X×2) +(3×3X) +(3×2)

=2X-2X^2- 3X^2 -2X +9X + 6

=6+9X-5X^2