x³+27y³+x²+6xy+9y² = x³+x²+27y³+9y²+6xy=x²(x+1)+9y²(3y+1)+6xy = (x²+9y²+6xy)(x+1)(3y+1)= (x²+2*x*3y+(3y)²)(x+1)(3y+1) = (x+3y)²(x+1)(3y+1)
x³+27y³+x²+6xy+9y² = x³+x²+27y³+9y²+6xy=x²(x+1)+9y²(3y+1)+6xy = (x²+9y²+6xy)(x+1)(3y+1)= (x²+2*x*3y+(3y)²)(x+1)(3y+1) = (x+3y)²(x+1)(3y+1)