Sagot :
C = (3-4x) (3-4x) - 5(3-4x)
facteur commun : (3-4x)
C = (3-4x) (3-4x -5)
C = (3-4x) (-4x-2)
C = -2 (3-4x) (2x + 1)
D = il faut penser à a² - b² = (a+b) (a-b)
= 8² - (5x)² = (8-5x) (8+5x)
E - idem..
E = (4x)² - (2x-1)² = (4x+2x-1) (4x-(2x-1) = (6x-1) (2x+1)
bonjour
apprends ta leçon, ça aide
C = ( 3 - 4 x ) ( 3 - 4 x - 5)
= ( 3 - 4 x ) ( - 4 x - 2 )
= 2 ( 3 - 4 x ) ( - 2 x - 1 )
D = ( 8 - 5 x ) ( 8 + 5 x ) = identité remarquable
E = ( 4 x + 2 x - 1 ) ( 4 x - 2 x + 1 )
= ( 6 x - 1 ) ( 2 x + 1 )