Show all work to factor x^4 − 5x^2 + 4 completely.

The answer is

Step-by-step explanation:

The first step to factor this expression should be to write the as a difference:

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Then using factorization by agrupation you get:

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Then using factorization by difference of two squares, using the formula:

So, we get:

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the answer is c. 23/3