bonjour j'ai besoin d'aide pour exercice de mathematique merci C=(x-7)(x+9) B=(x+3)(2x+4) D=(x-3)(4-4) E=(3x+4)(5x-7) F=(-2x+8)(4-x)

Bonsoir,

C=(x-7)(x+9)

= x²+9x -7x -63

= x² +2x -63

B=(x+3)(2x+4)

= 2x² +4x +6x +12

= 2x² +10x +12

D=(x-3)(4-4)

= 4x -4x -12 +12

= 0

E=(3x+4)(5x-7)

= 15x² -21x +20x -28

= 15x² -x -28

F=(-2x+8)(4-x)

= -8x +2x² +32-8x

= 2x² -16x + 32

C=(x-7)(x+9)

=(x×x)+(x×9)-(7×x)-(7×9)

=x^2+9x-7x-63

=x^2+2x-63

B=(x+3)(2x+4)

=(x×2x)+(x×4)+(3×2x)+(3×4)

=2x^2+4x+6x+12

=2x^2+10x+12

D=(x-3)(4-4)

=(x-3)(0)

=0

E=(3x+4)(5x-7)

=(3x×5x)-(3x×7)+(4×5x)-(4×7)

=15x^2-21x+20x-28

=15x^2-x-28

F=(-2x+8)(4-x)

=-(2x×4)+(2x×x)+(8×4)-(8×x)

=-8x+2x^2+32-8x

=2x^2-16x+32