Question

Letra d resolvida por delta (:

Answer 1

$x^2-4x=4\\x^2-4x-4=0\\\Delta=(-4)^2-4.1.(-4)\\\Delta=16+16\\\Delta=32$

$x= \frac{4\pm \sqrt{32} }{2}$

$x= \frac{4\pm \sqrt{2^2.2^2.2} }{2}$

$x= \frac{4\pm 4\sqrt{2} }{2}$

$\boxed{x_1=2-2 \sqrt{2} }$

$\boxed{x_2=2+2 \sqrt{2} }$