\(1,=\left(x-y^2\right)\left(x+y^2\right)\\ 2,=\left(9-y^2\right)\left(9+y^2\right)=\left(3-y\right)\left(3+y\right)\left(3+y^2\right)\\ 3,=\left(a-4b\right)\left(a^2+4ab+16b^2\right)\\ 4,=\left(x^3+y^3\right)\left(x^6-x^3y^3+y^6\right)\\ =\left(x+y\right)\left(x^2-xy+y^2\right)\left(x^6-x^3y^3+y^6\right)\\ 5,=\left(x+8y\right)^2\\ 6,=\left(2x-5y\right)^2\)
1) \(=\left(x-y^2\right)\left(x+y^2\right)\)
2) \(=\left(9-y^2\right)\left(9+y^2\right)=\left(3-y\right)\left(3+y\right)\left(9+y^2\right)\)
3) \(=\left(a-4y\right)\left(a^2+4ay+16y^2\right)\)
4) \(=\left(x^3+y^3\right)\left(x^6-x^3y^3+y^6\right)=\left(x+y\right)\left(x^2-xy+y^2\right)\left(x^6-x^3y^3+y^6\right)\)
5) \(=\left(x+8y\right)^2\)
6) \(=\left(2x-5y\right)^2\)
