Bonjour,
A= 15x² -21x +10x -14
= 15x² -11x -14
B= -24x² -8x -6x -2 +27x -12x² -9 +4x
= - 36x² +17x -7
C= 16x² -56x +49 -( 4 +32x + 64x² )
= 16x² -56x +49 - 4 -32x - 64x²
= -48x² - 88x +45
D=
(5x-2) ( 3x+1 -8x +5)
= (5x-2) ( -5x =6)
E =
(5x +3) ²
IR
F =
(7- 11x) ( 7+11x)
IR