Упростить выражение (5x+y/x-5y+5x-y/x+5y)÷x2+y2/x2-25y2=

Решите задачу:

$(\frac{5x+y}{x-5y} + \frac{5x-y}{x+5y} ) : \frac{x^2+y^2}{x^2-25y^2} = \frac{(5x+y)(x+5y) +(5x-y)(x-5y)}{(x-5y)(x+5y)} * \frac{x^2-25y^2}{x^2+y^2} = \\ \\ = \frac{5x^2+25xy +xy +5y^2 + 5x^2 -25xy -xy +5y^2}{(x-5y)(x+5y)} * \frac{x^2-(5y)^2}{x^2+y^2} = \\ \\ = \frac{10x^2+10y^2}{(x-5y)(x+5y)} * \frac{(x-5y)(x+5y)}{x^2+y^2} = \frac{10(x^2+y^2)(x-5y)(x+5y)}{(x-5y)(x+5y)(x^2+y^2)} = \frac{10}{1} = 10$