Question

СПАМЕРАМ БАН. Срочно помогите пожалуйста. Упростить выражение

Answer 1

$\frac{ {x}^{3} - 15x}{ {x}^{2} - 25 } - \frac{5}{x + 5} + \frac{x}{5 - x} - x - 15 = \frac{ {x}^{3} - 15x - 5(x - 5) + x( - (x + 5)) + ( - x - 15)( {x}^{2} - 25)}{ {x}^{2} - 25} = \frac{ {x}^{3} - 15x - 5x + 25 - {x}^{2} - 5x - {x}^{3} - 15 {x}^{2} + 25x + 375}{ {x}^{2} - 25} = \frac{ - 16 {x}^{2} + 400}{ {x}^{2} - 25 } = \frac{ - 16( {x}^{2} - 25)}{ {x}^{2} - 25} = - 16$

$\frac{ {x}^{3} - 4x}{x + 3} \times \frac{3x + 9}{ {x}^{2} + 4x + 5} \div \frac{ {x}^{2} - 2x }{2 + x} = \frac{x(x + 2)(x - 2)}{x + 3} \times \frac{3(x + 3)}{{x}^{2} + 4x + 5} \times \frac{x + 2}{x(x - 2)} = \frac{3(x + 2)(x + 2)}{ {x}^{2} + 4x + 5 } = \frac{3( {x}^{2} + 4x + 4)}{ {x}^{2} + 4x + 5} = \frac{3 {x}^{2} + 12x + 12 }{ {x}^{2} + 4x + 5}$