Here is an algorithm to try:

1. Import numpy and pandas
2. Define A = np.array([[1, 2, 1],[1, 3, 2]])
3. Split df of B in 2
4. Define df1 = pd.DataFrame("the first two rows of B")
5. Define df2 = pd.DataFrame("the next two rows of B")
6. result1, result2 = A * df1, A * df2
7. print the result

This is a pandas documentation on multiplication for reference