Réponses

2013-09-19T21:30:01+02:00
Bonsoir
a.(2x+1)²+(2-x)² = (4x²+4x +1)+ (4 - 4x +x²) = 4x² +4x +1 +4 -4x +x² = 5x² +5
b.(3x+4)(3x-4)-16
=9x² -16 -16 = 9x² - 32