Question

    c                 1           1
------------ : ( ---------- - ---- ) .
  b²- c²             b - c     b
Упростите

Answer 1

$\frac{c}{ {b}^{2} - {c}^{2} } \div ( \frac{1}{b - c} - \frac{1}{b} ) = \frac{b}{b + c} \\ 1)\frac{1}{b - c} - \frac{1}{b} = \frac{b - b + c}{b(b - c)} = \frac{ c}{b(b - c)} \\ 2) \frac{c}{ {b}^{2} - {c}^{2} } \div \frac{ c}{b(b - c)} = \frac{c \times b(b - c)}{(b - c)(b + c)c} = \frac{b}{b + c}$