Question

Упростите.Дам 20 баллов

Answer 1

${x}^{3} - 27 = (x - 3)( {x}^{2} + 3x + 9)$
${x}^{2} - 9 = (x - 3)(x + 3)$
поэтому

$\frac{{x}^{3} - 27}{ {x}^{2} + 3x + 9 } - \frac{x ^{2} - 9 }{x - 3} = \\ = \frac{(x - 3) \times({x}^{2} + 3x + 9) }{{x}^{2} + 3x + 9} - \\ - \frac{(x - 3)(x + 3)}{(x - 3)} = \\ = x - 3 - (x + 3) = \\ = x - 3- x - 3 = - 6$
Ответ: = - 6