Question

(a/a - y - a + y/a) * a - y/(2y) помогите пожалуйста

Answer 1

$\displaystyle\bf\\\Big(\frac{a}{a-y} -\frac{a+y}{a} \Big)\cdot\frac{a-y}{2y} =\frac{a\cdot a-(a+y)\cdot(a-y)}{a\cdot(a-y)} \cdot\frac{a-y}{2y} =\\\\\\=\frac{a^{2} -(a^{2}-y^{2} ) }{a\cdot(a-y)} \cdot\frac{a-y}{2y} =\frac{a^{2} -a^{2} +y^{2} }{a\cdot(a-y)} \cdot\frac{a-y}{2y} =\\\\\\=\frac{y^{2} }{a(a-y)} \cdot\frac{a-y}{2y}=\frac{y}{2a}$