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Math Help - Quick Easy Simple Task

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    Smile Quick Easy Simple Task

    Solve each of the following quadratic equation by factorising and applying the Null Factor Law.

    2x^2 - 5 = 0

    Please show complete steps!
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  2. #2
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    Quote Originally Posted by Joker37 View Post
    Solve each of the following quadratic equation by factorising and applying the Null Factor Law.

    2x^2 - 5 = 0

    Please show complete steps!
    2x^2 - 5 = 0

    2\left(x^2 - \frac{5}{2}\right) = 0

    2\left[x^2 - \left(\sqrt{\frac{5}{2}}\right)^2\right] = 0

    2\left(x + \sqrt{\frac{5}{2}}\right)\left(x - \sqrt{\frac{5}{2}}\right) = 0

    So by Null Factor Law

    x + \sqrt{\frac{5}{2}} = 0 or x - \sqrt{\frac{5}{2}} = 0

    x = -\sqrt{\frac{5}{2}} or x = \sqrt{\frac{5}{2}}.

    If you have to rationalise the denominator, you should end up with

    x = -\frac{\sqrt{10}}{2} or x = \frac{\sqrt{10}}{2}.
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