Question 1172469
I will solve 4x^2=11x+21 since there needs to be a power of 2 somewhere.
4x^2-11x-21=0
x=(1/8)(11+/-sqrt(121+336)); sqrt term=21.3776
x=(1/8)(32.3776)=4.05
and 
x=(1/8)(-10.3776)=-1.30
{{{graph(300,300,-5,5,-25,25,4x^2-11x-21)}}}