Bonsoir,
Développer :
Double distributivité :
- (a + b)(c + d) = ac + ad + bc + bd
A = (2y + 1)(y + 3)
A = 2y*y + 2y*3 + 1*y + 1*3
A = 2y² + 6y + y + 3
A = 2y² + 7y + 3
B = (y - 5)(y - 2)
B = y*y + y*(-2) + (-5)*y + (-5)*(-2)
B = y² - 2y - 5y + 10
B = y² - 7y + 10
C = (4a + 3)(3a + 2)
C = 4a*3a + 4a*2 + 3*3a + 3*2
C = 12a² + 8a + 9a + 6
C = 12a² + 17a + 6
D = (3 - 2a)(a + 1)
D = 3*a + 3*1 + (-2a)*a + (-2a)*1
D = 3a + 3 - 2a² - 2a
D = -2a² + a + 3
* = multiplication
Bonne soirée.
