Pls help!!

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! :)