WEBVTT

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Here is the problem: A times B: A equals [[1, 2], [3, 4]].

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Compute A times B exactly.

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Read matrix A.

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Read matrix B.

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Each entry is a row of A dotted with a column of B. The result is 2 times 2.

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Result.

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So the answer is A times B equals [[19, 22], [43, 50]].

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A is 2 times 2 and B is 2 times 2, so AB is 2 times 2. Matrix multiplication is not commutative: BA is generally different.

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All arithmetic is exact (fractions, no rounding).