1) 3ах+4a=а(3х+4)
2)6x^2-3x=3х(2х-1)
3)18x^4+12x^3=6х^3(3x+2)
4)-a^7-5a^11-3a^6=a^6(-a-5a^5-3)
5)8x^4y^2-12x^2y^3+4x^2y^2=4x^2y^2(2x^2-3y+1)
6) ax+3ay+5x+15y=a(x+3y)+5(x+3y)=(x+3y)(a+5)
7)x^5+2x^4-x-2=x^4(x+2)-(x+2)=(x+2)(x^4-1)=(x+2)(x²-1)(x²+1)=(x+2)(x-1)(x+1)(x²+1)
8)ab-ac-a^2+bc=ab+bc-ac-a²=b(a+c)-a(c+a)=(a+c)(b-a)