Question

(a+2/a-2-a-2/a+2): a2+4/4-a2 СРОЧНО!!!

Answer 1

$(\frac{a+2}{a-2}-\frac{a-2}{a+2}):\frac{a^{2}+4 }{4-a^{2} } =\frac{(a+2)(a+2)-(a-2)(a-2)}{(a+2)(a-2)} *\frac{(2-a)(2+a)}{a^{2} +4} =\\ \\ \frac{a^{2}+4a+4-a^{2} +4a-4 }{a^{2} +4} =\frac{8a}{a^{2} +4}$