Cx²-cy²=c(x²-y²)= c(x-y)(x+y)
x³-4x=x(x²-4)= x(x-2)(x+2)
2y³-18y= 2y(y²-9)= 2y(y-3)(y+3)
12b²-12c²= 12(b²-c²)= 12(b-c)(b+c)
2a^2c-2b^2c=2(a^2c-b^2c)= 2(a²-b²)^c=2(a-b)(a+b)^c
7y³-7y=7y(y²-1)= 7y(y-1)(y+1)
a³-a^5= a³(1-a²)= a³(1-a)(1+a)
5m²+5n²-10mn= 5(m+n)²-10mn= 5(m²+2mn+n²)-10mn= 5m²+10mn+5n²-10mn=5(m+n)²
x^2y+14xy²+49y³= x^2y+7y²(2x+7y)
a^4-b^4=(a²-b²)(a²+b²)=(a-b)(a+b)(a+b)²
2m³-16=2(m³-8)= 2 (m³-2³)= 2(m-2)(m²+2m+4)
-x^4+27x= -x(x³-27)= -x(x³-3³)= -x(x-3)(x²+3x+9)