développer et réduire les expressions A= 2 ( x + 3 ) - 5 ( x - 4 ) B = -3 (3 - x) +4 ( 2 - x) C= 9 (x -y +2) - ( 3x +2y -5 ) D= a (b - a) -b ( a + b) E= ( x - 2

Bonjour,

A= 2 ( x + 3 ) - 5 ( x - 4 )
A = 2x + 6 - 5x + 20
A = 2x - 5x + 6 + 20
A = - 3x + 26

B = -3 (3 - x) +4 ( 2 - x)
B = - 9 + 3x + 8 - 4x
B = 3x - 4x - 9 + 8
B = - x - 1

C= 9 (x -y +2) - ( 3x +2y -5 )
C = 9x - 9y + 18 - 3x - 2y + 5
C = 9x - 3x - 9y - 2y + 18 + 5
C = 6x - 11y +23

D= a (b - a) -b ( a + b)
D = ab - a² - ab - b²
D = - a² - b² 

E= ( x - 2 ) ( 5 - x )
E = 5x - x² - 10 + 2x
E = - x² + 5x + 2x - 10
E = - x² + 7x - 10