Factor the polynomials
25x^{4}-9y^{2}
49x^{4}-16y^{2}
9x^{4}-64y^{2}
2x^{3}-18x
5x^{3}-245x
3x^{3}-48x
9x^{2}-21x+10
25x^{3}+70x^{2}+33x
4x^{3}-8x^{2}-21x