A(x)=(3+5x)²-(4x-7)(3+5x)
= 3²+2x3x5x+(5x)² - (4x-7) (3+5x)
= 9+ 30x+ 25x² - 12x+ 20x²-21-35x
60x²-17x-12
A(x)=(3+5x)²-(4x-7)(3+5x)=(3+5x)(3+5x-4x-7)=(3+5x)(x-4)
bonne chance
