Question 120627
{{{4x^2-13x=12}}}
{{{4x^2-13x-12=0}}} (Subtract 12 from both sides)
{{{(4x+3)(x-4)=0}}} (Factor)

Which gives 
{{{4x+3=0}}} or {{{x-4=0}}}
implies {{{x=-3/4}}} or {{{x=4}}}