Question

x la a doua - 16 totul supra x la a doua - 4x

Answer 1

$\frac{ x^{2} -16}{ x^{2} -4x} = \frac{ x^{2} - 4^{2} }{ x(x -4)}= \frac{(x-4)(x+4)}{x(x-4)} = \frac{(x+4)}{x}$

Answer 2

( x² - 16) / x² - 4x = ( x² - 4²) / x( x - 4) = ( x - 4)( x + 4) / x( x - 4) =
                           = ( x + 4) / x