1.81x^4-y^42.36a²-（a²+9）²3.(x-y)^3-4(x-y)^2+4(x-y)4.x²-6x+9-y²5.ax-ay+x²-y²

Question

1.81x^4-y^4
2.36a²-（a²+9）²
3.(x-y)^3-4(x-y)^2+4(x-y)
4.x²-6x+9-y²
5.ax-ay+x²-y²

Answer 1

1.81x^4-y^4
=(9x^2)^2-(y^2)^2
=(9x^2+y^2)(9x^2-y^2)
=(9x^2+y^2)(3x+y)(3x-y)
2.36a^2-（a^2+9）^2
=(6a+a^2+9)(6a-a^2-9)
=-(a+3)^2(a-3)^2
3.(x-y)^3-4(x-y)^2+4(x-y)
=(x-y)[(x-y)^2-4(x-y)+4].
=(x-y)(x-y-2)^2
4.x^2-6x+9-y^2
=(x-3)^2-y^2
=(x-3+y)(x-3-y)
5.ax-ay+x^2-y^2
=a(x-y)+(x+y)(x-y)
=(x-y)(a+x+y)