Answer
Invertibel
Work Step by Step
We know that the determinant of a matrix \[
\left[\begin{array}{rr}
a & b &c\\
d &e &f\\
g & h & i
\end{array} \right]
\]
is $D=aei+bfg+cdh-ceg-afh-bdi$.
Also, a matrix is non-invertible if and only if $D=0$.
Hence here $D=(-1)(-2)5+2.1.8+3.5.(-2)-3.(-2)8-(-1).1(-2)=1-1=-8$, thus the matrix is invertible.