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    How would you factorise this  x^4 + 7x^2 - 8

    & Where can I find these sort of expressions to practice on?
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    (Original post by animemaniac132)
    How would you factorise this  x^4 + 7x^2 - 8

    & Where can I find these sort of expressions to practice on?
    I think you need to say let u = x^2, then you get a quadratic in u.
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    (Original post by animemaniac132)
    How would you factorise this  x^4 + 7x^2 - 8

    & Where can I find these sort of expressions to practice on?
    This is a quadratic in x^2. Either work with that directly or let u = x^2 to get u^2 + 7u - 8 = 0, solve and then back-substitute.
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    (Original post by Zacken)
    This is a quadratic in x^2. Either work with that directly or let u = x^2 to get u^2 + 7u - 8 = 0, solve and then back-substitute.
    Oh, I had never seen this before. That makes a bit of sense now, do you think this could come up in c1
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    (Original post by animemaniac132)
    Oh, I had never seen this before. That makes a bit of sense now, do you think this could come up in c1
    Yes.
 
 
 
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