СРОЧНООО!!! РЕШИТЕ НОМЕР 3 !!!!

Решите задачу:

$1)\;\left(\frac m{m-n}-\frac m{m+n}\right):\frac{16m^3n}{m^2-n^2}=\frac{m(m+n)-m(m-n)}{(m-n)(m+n)}\cdot\frac{m^2-n^2}{16m^3n}=\\=\frac{m^2+mn-m^2+mn}{m^2-n^2}\cdot\frac{m^2-n^2}{16m^3n}=\frac{2mn}{16m^3n}=\frac1{8m^2}$

$2)\;\left(\frac1{4x^2}-\frac1{xy}+\frac1{y^2}\right)\cdot\left(\frac1{2x-y}-\frac1{y-2x}\right)-\frac1{xy^2}=\frac{y^2-4xy+4x^2}{4x^2y^2}\cdot\left(\frac1{2x-y}+\frac1{2x-y}\right)-\frac1{xy^2}=\\=\frac{(2x-y)^2}{4x^2y^2}\cdot\frac2{2x-y}-\frac1{xy^2}=\frac{2(2x-y)}{4x^2y^2}-\frac1{xy^2}=\frac{4x-2y-4x}{4x^2y^2}=-\frac{2y}{4x^2y^2}=-\frac1{2x^2y}$