Question

срочно пж нужно дам 50 баллов ​

Answer 1

1)

$\frac{ {a}^{2} - {c}^{2} }{a + b} \times \frac{ {a}^{2} - b {}^{2} }{ac + {c}^{2} } \times (a - \frac{ac}{a + c} ) = \\ = \frac{(a - c)(a + c)(a - b)(a + b)}{(a + b) \times c(a + c)} \times \frac{a(a + c) - ac}{a + c} = \frac{(a - c)(a - b)}{c} \times \frac{ {a}^{2} + ac - ac}{a + c} = \\ = \frac{ {a}^{2}(a - c)(a - b) }{c(a + c)} = \frac{ {a}^{2} ( {a}^{2} - ab - ac + bc) }{ac + {c}^{2} } = \frac{ {a}^{4} - {a}^{3}b - {a}^{3} c + {a}^{2} bc}{ac + {c}^{2} }$

2)

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