Question 119129
{{{2x^2-7x=4}}} Start with the given equation



{{{2x^2-7x-4=0}}}  Subtract 4 from both sides.



{{{(x-4)(2x+1)=0}}} Factor the left side (note: if you need help with factoring, check out this <a href=http://www.algebra.com/algebra/homework/playground/change-this-name4450.solver>solver</a>)




Now set each factor equal to zero:

{{{x-4=0}}} or  {{{2x+1=0}}} 


{{{x=4}}} or  {{{x=-1/2}}}    Now solve for x in each case



So our answer is 

 {{{x=4}}} or  {{{x=-1/2}}} 



Notice if we graph {{{y=2x^2-7x-4}}} we can see that the roots are {{{x=4}}} and  {{{x=-1/2}}} . So this visually verifies our answer.



{{{ graph(500,500,-10,10,-10,10,0, 2x^2-7x-4) }}}