Question

Solve for x: 2x^2+4x-16+=0

Answer 1

$2x^2+4x-16=0|:2\\ x^2+2x-8=0\\ \Delta=36\Rightarrow\sqrt{\Delta}=6\\ x_1=\frac{-b+\sqrt{\Delta}}{2a}\ \vee\ x_=\frac{-b-\sqrt{\Delta}}{2a}\\ x_1=2\ \vee\ x_2=-4$

Answer 2

$2x^2+4x-16=0\ /:2\\ \\x^2+2x-8=0\\ \\x^2-2x+4x-8=0\\ \\x(x-2)+4(x-2)=0\\ \\(x-2)(x+4)=0\ \ \ \Leftrightarrow\ \ \ x-2=0\ \ \ \vee\ \ \ x+4=0\\ \\.\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ x=2\ \ \ \ \ \ \ \ \ \ \ \ \ \ x=-4$