Question

помогите решить номер 3 умоляю

Answer 1

$1) frac{2x + 5}{ {x}^{2} + 4x + 4} = frac{2x + 5}{ {(x + 2)}^{2} } \ frac{2x + 5}{ {(x + 2)}^{2} } - frac{x + 3}{x(x + 2)} = frac{x(2x + 5)}{ x( {x + 2)}^{2} } - frac{( x + 3)(x + 2)}{x {(x + 2)}^{2} } = \ frac{ 2 {x}^{2} + 5x - ({x}^{2} + 5x + 6 )}{x( {x + 2)}^{2} } = frac{ {x}^{2} - 6}{x( {x}^{2} + 4x + 4)}$
$2) frac{ {x}^{2} - 6 }{x( {x + 2)}^{2} } times frac{ { x }^{3} - 4x }{ {x}^{2} - 6 } = frac{ {x}^{3} - 4x}{x {(x + 2)}^{2} } = frac{x( {x}^{2} - 4 ) }{ x( {x + 2)}^{2} } = frac{( x - 2 ) (x + 2)}{ ( {x + 2)}^{2} } = frac{x - 2}{x + 2}$
x-2/x+2=x-2/x+2
Тождество доказано.