Bonjour !
Exercice 1
[tex]A = 18x + 10 + 11+17x\\A= 35x+21\\A=7(3+5x)\\\\B= 30x^2+45x\\B=x (30x+45)\\\\C= 12x-8x^2\\C= x(12-8x)\\\\D=42x^2+60x+18x^2+30x\\D=60x^2+90x\\D=x(60x+90)[/tex]
Au plaisir !
