Question

Помогите решить пример "Б"

Answer 1

$\frac{16 {a }^{2} - 25 {c}^{2} }{ac + {c}^{2} } \div \frac{5c - 4a}{3c} + \frac{13a + 14c}{a + c } = \frac{(4a - 5c)(4a + 5c)}{c(a + c)} \times \frac{3c}{ - (4a - 5c) } + \frac{13a + 14c}{a + c} = \frac{ - 3(4a + 5c)}{a + c} + \frac{13a + 14c}{a + c} = \frac{ - 12a - 15c + 13a + 14c}{a + c} = \frac{a - c}{a + c}$