Упростите вырождение

Решите задачу:

$1)\frac{5a^2+3ab}{a^2-0,36b^2}=\frac{5a(a+0,6b)}{(a-0,6b)(a+0,6b)}=\frac{5a}{a-0,6b}\\\\\\2)\frac{8y^3-1}{y-4y^3}=\frac{(2y)^3-1^3}{y(1-4y^2)}=\frac{(2y-1)(4y^2+2y+1)}{y(1-2y)(1+2y)}=-\frac{(2y-1)(4y^2+2y+1)}{y(2y-1)(1+2y)}=-\frac{4y^2+2y+1}{y(1+2y)}\\\\\\3)\frac{xy}{x^2y-xy^2}=\frac{xy}{xy(x-y)}=\frac{1}{x-y}\\\\\\4)\frac{ax-bx}{a-b}=\frac{x(a-b)}{a-b}=x$