Решение:
\[ \frac{3 \cdot x}{x(x-5)} + \frac{5 \cdot x(x-5)}{x(x-5)} = \frac{(x+3) \cdot (x-5)}{x(x-5)} \]
\[ \frac{3x}{x(x-5)} + \frac{5x(x-5)}{x(x-5)} = \frac{(x+3)(x-5)}{x(x-5)} \]
\[ 3x + 5x^2 - 25x = x^2 - 5x + 3x - 15 \]
\[ 5x^2 - 22x = x^2 - 2x - 15 \]
\[ 5x^2 - x^2 - 22x + 2x + 15 = 0 \]
\[ 4x^2 - 20x + 15 = 0 \]
В нашем случае $$a=4$$, $$b=-20$$, $$c=15$$.
\[ D = (-20)^2 - 4 \cdot 4 \cdot 15 = 400 - 16 \cdot 15 = 400 - 240 = 160 \]
\[ \sqrt{D} = \sqrt{160} = \sqrt{16 \cdot 10} = 4\sqrt{10} \]
\[ x_1 = \frac{20 + 4\sqrt{10}}{2 \cdot 4} = \frac{20 + 4\sqrt{10}}{8} = \frac{4(5 + \sqrt{10})}{8} = \frac{5 + \sqrt{10}}{2} \]
\[ x_2 = \frac{20 - 4\sqrt{10}}{2 \cdot 4} = \frac{20 - 4\sqrt{10}}{8} = \frac{4(5 - \sqrt{10})}{8} = \frac{5 - \sqrt{10}}{2} \]
Ответ: $$x_1 = \frac{5 + \sqrt{10}}{2}$$, $$x_2 = \frac{5 - \sqrt{10}}{2}$$