Problem:
Compute the rank of
$\left(
\begin{array}{ccccc}
 4 & -5 & 3 & -5 & -8 \\
 -8 & -6 & -8 & -3 & 7 \\
 7 & -4 & -9 & -8 & -2 \\
 0 & -4 & -4 & -5 & 9 \\
\end{array}
\right)$.
Answer:
$4$
{'source': 'AMPS', 'file': 'amps/mathematica/linear_algebra/rank_and_nullity/12027.txt'}