Bonsoir,
A =-3( 5x - 1)
= -15x +3
B = 3( 4 + 3x )
=12 +9x
D= ( 3x + 7)(5x + 3)
= 15x² +9x +35x +21
= 15x² +44x +21
E = ( 6x +4)(3 - 4x)-(4x+7)(5x+3)
= 18x -24x² +12 -16x -( 20x² +12x +35x+21)
=18x -24x² +12 -16x - 20x² -12x -35x-21
= -44x² -45x -9
C=-2( 7x - 1). 5( 4 + 3x)
quel signe?
F= -3(2x + 4)(3 - 4x)
= (-6x -12)( 3-4x)
= -18x +24x² -36 +48x
= 24x²+ 31x -36