Problem:
Multiply
$\left(
\begin{array}{cc}
 -\frac{5}{7} & -\frac{1}{7} \\
 \frac{12}{7} & -\frac{2}{7} \\
 0 & -\frac{4}{7} \\
\end{array}
\right)$ and
$\left(
\begin{array}{ccccc}
 -\frac{12}{7} & -\frac{13}{7} & -\frac{15}{7} & -\frac{5}{7} & \frac{3}{7} \\
 \frac{9}{7} & -\frac{16}{7} & -\frac{13}{7} & -\frac{17}{7} & -\frac{6}{7} \\
\end{array}
\right)$.
Answer:
$\left(
\begin{array}{ccccc}
 \frac{51}{49} & \frac{81}{49} & \frac{88}{49} & \frac{6}{7} & -\frac{9}{49} \\
 -\frac{162}{49} & -\frac{124}{49} & -\frac{22}{7} & -\frac{26}{49} & \frac{48}{49} \\
 -\frac{36}{49} & \frac{64}{49} & \frac{52}{49} & \frac{68}{49} & \frac{24}{49} \\
\end{array}
\right)$
{'source': 'AMPS', 'file': 'amps/mathematica/linear_algebra/multiply/25095.txt'}