Question 119642
{{{4x = - 16x^2}}}

Add {{{16x^2}}} to both sides of the equation to get

{{{16x^2 + 4x = 0}}}.

Now factor 4x out of the expression on the left hand side of the equation to get

{{{4x(4x + 1) = 0}}}.

This tells us that {{{x = 0}}} or {{{4x +1 = 0}}} which implies that {{{x = 0}}} or {{{x = -1/4}}}.