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Can somone pls help with this?

 May 17, 2021
 #1
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1) 8x2 - 72 = 0 

    x2 - 9 = 0

    x2 = 9

    x = ± 3

 

2) https://gyazo.com/33805f53504404d1923cc25f58131c22 (drew it out for you)

3) \(25x^2 + 20x = 6\)

    \(25x^2 + 20x - 6 = 0\)

    \(x^2 + \frac{4}{5}x - \frac{6}{25} = 0\)

    \(x^2 + \frac{4}{5}x + \frac{4}{25} - \frac{4}{25} - \frac{6}{25} = 0\)

    \((x + \frac{2}{5})^2 - \frac{10}{25} = 0\)

    \((x + \frac{2}{5})^2 = \frac{10}{25}\)

    \(x + \frac{2}{5} = \frac{\sqrt{10}}{5}\)

    \(x = -\frac{2 ± \sqrt{10}}{5}\)

 

4) \(4x^2 + 6x = 8\)

    \(4x^2 + 6x - 8 = 0\)

    \(x = {-b \pm \sqrt{b^2-4ac} \over 2a}\)

    \(x = {-(6) \pm \sqrt{(6)^2-4(4)(-8)} \over 2(4)}\)

    \(x = {-6 \pm \sqrt{36+128} \over 8}\)

    \(x = {-3 \pm \sqrt{164} \over 4}\)

    \(x = {-3 \pm 2\sqrt{41} \over 4}\)

 

Please tell me if I did anything wrong! :)

 May 17, 2021

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