Answer:
gyuggbgzsZdxfghuiguyftdrtffyurtyryjjb
Step-by-step explanation:
Answer:
9!=362880 ways
Step-by-step explanation:
It is given that there are 4 different mathematics books and 5 different science books.
So basically there are 9 different books. So we have 9 choices for the first book, 8 choices for the second book, since we have placed the first one. We have 7 choices for the third book and so on. Therefore, we can arrange 9 different books in,
!9 ways, on solving !9 we get,

So there are 362,880 ways to arrange 9 different books if there are no restrictions.
It is convenient to let a calculator do the math.
.. (x, y) = (0, 3) . . . . . your 3rd selection
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I prefer using the RREF function to put the augmented matrix into reduced row-echelon form. If the equations are dependent or inconsistent, using that method tells you so without giving a matrix inversion error.