Question dc252b23

Advanced Math - Equivalent expressions

$f (x) = x^{2} + b x$

$g (x) = 9 x^{2} - 27 x$

Functions $f$ and $g$ are given, and in function $f$ , $b$ is a constant. If $f (x) \cdot g (x) = 9 x^{4} - 26 x^{3} - 3 x^{2}$ , what is the value of $b$ ?