The equation is
.
Subtract 11 from each side.
\

Compare the equation with
.
a = 4, b = 7 and c =
.
a) Now we can find discriminant value
\
(Substitute a = 4, b = 7 and c =
)

Product of two same sings is positive.
\

b) The discriminant is positive, so the equation have two rational roots.
\c) Apply quadratic formula: 
(Replace
, a with 4, and b with 7)





The solutions are
.
The discriminant value is 225 and the equation have two complex roots.
\The solutions are
.