1) 6y^6 - 6x^2y^4 = 6y^4(y^2 - x^2) = 6y^4(y - x)(y + x)
2) 2x^2 - 28xy + 98y^2 = 2(x - 7y)(x - 7y) = 2(x - 7y)^2
3) -18n^8 + 12n^6 - 2n^4 = -2n^4(9n^4 - 6n^2 + 1) = -2n^4(3n^2 - 1)^2
1) 6y^6 - 6x^2y^4 = 6y^4(y^2 - x^2) = 6y^4(y - x)(y + x)
2) 2x^2 - 28xy + 98y^2 = 2(x - 7y)(x - 7y) = 2(x - 7y)^2
3) -18n^8 + 12n^6 - 2n^4 = -2n^4(9n^4 - 6n^2 + 1) = -2n^4(3n^2 - 1)^2