Question

Factor u⁴+7u²-8

honestly I'm just confused how to solve ;-; I see the answer is (u-1)(u-1)(u²+8) but I'm not sure how to show the work.
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Answer 1

`(u - 1)(u + 1)( {u}^(2) + 8)`

Explanation:

`{u}^(4) + 7 {u}^(2) - 8 \\ = {u}^(4) + 8 {u}^(2) - {u}^(2) - 8 \\ = {u}^(2) ( {u}^(2) + 8) - 1( {u}^(2) + 8) \\ = ( {u}^(2) - 1)( {u}^(2) + 8) \\ = (u - 1)(u + 1)( {u}^(2) + 8) \\`

Answer 2

(u + 1)(u - 1)(u² + 8)

Explanation:

Here is the steps:

• u⁴ + 7u² - 8 =
• u⁴- u² + 8u²-8 =
• u²(u² - 1) + 8(u² -1) =
• (u² - 1) (u² +8) =
• (u + 1)(u - 1)(u² + 8)