Sagot :
Réponse:
tu dois factoriser.
A=.(7x+3)(x-5)
A= 7x^2-35x+3x-15
A=7x^2-32x-15
B= (3x+2)(x-5)-(x+3)
B= 3x^2-15x+2x-10-x-3
B= 3x^2-14x-13
C= (17-4x)(7+4x)
C= 119+61x-28x-16x^2
C= 16x^2+33x+119
x^2 c est x au carré
A=7xcarré-35x+3x-15 A=7xcarré-32x-15
B=(3xcarré-13x+10)-(x+3) = 3xcarré-14x+7
C=119+68x-28x-16xcarré = 118+40x-16xcarré
B=(3xcarré-13x+10)-(x+3) = 3xcarré-14x+7
C=119+68x-28x-16xcarré = 118+40x-16xcarré