Question 337652
{{{2x^2+9x+4=0}}}
You could factor, complete the square, or use the quadratic formula. 
Factor this quadratic.
{{{(2x+1)(x+4)=0}}}
Two solutions, use the zero product property.
{{{2x+1=0}}}
and 
{{{x+4=0}}}
Solve those two equations to find the zeros of your function.