2 - Développez et réduisez les expressions suivantes : A = (x + 3)(y + 2) B = (3-2x)(4 - x) D = 2a(1 - a) - (a - 3)(3a + 2) E = (x + 2)(4x - 3) - X(7 - x) C = 2

bonjour

A = (x + 3)(y + 2)

A = xy + 2 x + 3 y + 6

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

B = 12 - 3 x - 8 x + 2 x²

B = 2 x² - 11 x + 12

D = 2a(1 - a) - (a - 3)(3a + 2)

D = 2 a - 2 a² - ( 3 a² + 2 a - 9 a - 6 )

D =  - 2 a² + 2 a - 3 a² - 2a + 9 a + 6

D = - 5 a² + 9 a + 6

E = (x + 2)(4x - 3) - X(7 - x)

E = 4 x² - 3 x + 8 x - 6 - 7 x + x²

E = 5 x² - 2 x - 6

C = 2(3 + x)(3 - x)

C = 2 (9 - x²)

C =  18 - 2 x²

Bonjour,

Développez et réduisez les expressions suivantes :

A = (x + 3)(y + 2)= xy+3y+2x+6

B = (3-2x)(4 - x)= 12-8x-3x+2x²= 2x²-11x+12

D = 2a(1-a)-(a-3)(3a+2)=2a-2a²-(3a²-9a+2a-6)= -2a²+2a-3a²+7a-6= -5a²+9a+6

E = (x + 2)(4x - 3) - X(7 - x)=4x²+8x-3x-6-7x+x²=  5x²-2x-6

C = 2(3 + x)(3 - x)= 2(9+3x-3x-x²)= -2x²+18