Решите пж 2 и 3 пример:

Решите задачу:

$\displaystyle 4)..\frac{a^{2}-6a+9}{a^{2}-4}: \frac{2a-6}{a+2}*(a-2)^{2}= \frac{(a-3)^{2} }{(a-2)(a+2)}* \frac{(a+2)(a-2)^{2}}{2(a-3)}= \\ \\= \frac{(a-3)(a-2)}{2}=0,5a^{2}-2,5a+6; \\ \\ 3).. \frac{2}{4 x^{2}-y^{2}}* \frac{y-2x}{4x}= \frac{y-2x}{2x(2x-y)(2x+y)}=- \frac{1}{2x(2x+y)}= \\ \\ =-\frac{1}{4x^{2}+2xy}; \\ \\ 2).. \frac{ax-xy}{a}: \frac{a^{2}-ay}{x}= \frac{x(a-y)}{a}* \frac{x}{a(a-y)}=\frac{ x^{2}}{a^{2} };$