(4x²-2xy)/(12x²-3y²)=2x(2x-y)/3(4x²-y²)=
2x(2x-y)/3(2x-y)(2x+y)=2x/3(2x+y)
(a²-x²)/(a+x)=(a-x)(a+x)/(a+x)=a-x
(14x^5+7x⁴y)/(10xy³+5y⁴)=7x⁴(2x+y)/5y³(
2x+y)=7x⁴/5y³
(x²-y²)/(y-x)=(x-y)(x+y)/(y-x)=(x-y)(x+y)/-(-y+x)=(x+y)/-1
(12x⁴+27x³c)/(16x³c+36x²c²)=
3x³(4x+9c)/4x²c(4x+9c)=3x³/4x²c
(14x^5+7x⁴y)/(10xy³+5y⁴)=7x⁴(2x+y)/5y³(2x+y)=7x⁴/5y³