1)6x^2-6xy-8x+8y=6x(x-y)-8(x-y)=(6x-8)(x-y)=(6•(-4)-8)(-4-2)=(-24-8)(-6)=(-16)•(-6)=96
2)a^2-ab-5a+5b=a(a-b)-5(a-b)=(a-5)(a-b)=(-1)•(1/4+1/2)=(-1)•3/4=-3/4
3)b^2+bc+ab+ac=b(b+a)+c(b+a)=(b+c)(b+a)=(-2,5)•(-3)=7,5
4)3xy-x^3y^3-6+2x^2y^2=3(xy-2)-x^2y^2(xy-2)=(3-x^2y^2)(xy-2)=(3-1/4)(-1/2-2)=11/4•(-5/2)=-55/8=-6 7/8