Answer
$-13$
Work Step by Step
Substituting $a=-1$, $b=-2$, and $c=4$, the given expression, $
\dfrac{9a+2b}{a+b+c}
,$ evaluates to
\begin{array}{l}\require{cancel}
\dfrac{9(-1)+2(-2)}{(-1)+(-2)+4}
\\\\=
\dfrac{-9-4}{-1-2+4}
\\\\=
\dfrac{-13}{1}
\\\\=
-13
.\end{array}
