Réponses

2013-03-17T15:35:56+01:00

B= 7x + 28 - (10x-15)(2x+3)

= 7x + 28 -20x^2 -30x +30x + 45 

= -20x^2 +7x + 73

2013-03-17T15:39:25+01:00
=7x+28-5(4x^(2)-9)
=7x+28-20x^2+45
= 20x^2 +7x +73