factoriser (4x+12)(-5x+2)-(5x+1)(x+3)+(6x-13)(2x+6)
(4x+12)(-5x+2)-(5x+1)(x+3)+(6x-13)(2x+6)
=(4(x+3))(-5x+2)-(5x+1)(x+3)+(6x-13)2(x+3)
=(x+3)(4(-5x+2)-5x-1+2(6x-13))
=(x+3)(-20x+8-5x-1+12x-26)
=(x+3)(-13x-19)
(4x+12)(-5x+2)-(5x+1)(x+3)+(6x-13)(2x+6)= 4 (x+3)(-5x+2)-(5x+1)(x+3)+(6x-13)2(x+3)
(x+3)(-20x+4-5x-1+12x-26)=(x+3)(-13x-23)
bonne chance