Bonjour,

Factoriser les expressions

7x²-4x= x(7x-4)

21a²-14b= 7(3a²-2b)

(2x-1)(x+3)+5(x+3)= (x+3)(2x-1+5)= (x+3)(2x+4)= 2(x+3)(x+2)

2x(2x-1)-(4x-5)(2x-1)= (2x-1)(2x-4x+5)= (2x-1)(-2x+5)= - (2x-1)(2x-5)