а) \( \frac{x^2 - xy}{xy} = \frac{x(x-y)}{xy} = \frac{x-y}{y} \)
б) \( \frac{xy}{x^2y + xy^2} = \frac{xy}{xy(x+y)} = \frac{1}{x+y} \)
в) \( \frac{a^2 + ab}{2a + 2b} = \frac{a(a+b)}{2(a+b)} = \frac{a}{2} \)
г) \( \frac{5c^2 + c}{2 + 10c} = \frac{c(5c+1)}{2(1+5c)} = \frac{c}{2} \)
Ответ: а) \( \frac{x-y}{y} \); б) \( \frac{1}{x+y} \); в) \( \frac{a}{2} \); г) \( \frac{c}{2} \).