Question

What is the factored form of x2 - 9x + 20?

A. x(x - 9) + 20
B. (x-4)(x + 5)
C. (x - 4)(x - 5)
D. (x2 - 4)(x2 - 5)

Answer 1

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Answer: Option C, (x - 4)(x - 5)

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Given:
`\textsf{x}^2\textsf{ - 9x + 20}`

Find:
`\textsf{Determine the factored form}`

Solution: In order to factor the given equation, we need to first determine two numbers which add up to -9 and multiply to become 20. We can think of the factors of 20 which would add up to -9 and the one that matches that description would be -5 and -4. These two numbers multiply to become 20 and combine to become -9. Now that we have that information, we can break up the quadratic into two separate roots using the two numbers that we found.

Therefore, the answer would be Option C, (x - 4)(x - 5).