Нужна помощь помогите

1) $\frac{1}{3x+y} - \frac{1}{3x-y} = \frac{3x-y -3x-y}{(3x+y)(3x-y)} = -\frac{2y}{(3x+y)(3x-y)}$
2) $\frac{3-2a}{2a} - \frac{1- a^{2} }{ a^{2} } = \frac{3a-2 a^{2}-2+2 a^{2} }{2 a^{2} } = \frac{3a-2 }{2 a^{2} }$
3) $\frac{5y}{ y^{2}-2y } = \frac{5}{y-2}$
4) $\frac{2}{x-4} - \frac{x+8}{(x-4)(x+4)} - \frac{1}{x} = \frac{2x^{2}+8x- x^{2}-8x- x^{2}+16 }{x(x-4)(x+4)} = \frac{16}{x(x-4)(x+4)}$
$\frac{2}{x-4} - \frac{x+8}{(x-4)(x+4)} - \frac{1}{x} = \frac{2x(x+4)- x^{2}-8x- x^{2}+16 }{x(x-4)(x+4)}$