Sagot :
Bonjour,
2a -14 +3a² -21a
= 3a² -19a - 14
10x -8x² -6x +21
= -8x² +4x +21
(a+b)² = a² +2ab + b²
(a-b)² = a² -2ab +b²
a² -b² = (a-b) (a+b)
Bonjour,
2a -14 +3a² -21a
= 3a² -19a - 14
10x -8x² -6x +21
= -8x² +4x +21
(a+b)² = a² +2ab + b²
(a-b)² = a² -2ab +b²
a² -b² = (a-b) (a+b)