Answer
Invertible
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 $D=2.5.1+6.1.2+3.0.(-1)-2.(-1).5-2.1.0-6.3.1=14 \ne 0$, thus the matrix is invertible.
