Answer:
x² - 20 = 0
Using the quadratic formula
[tex]x = \frac{ - b± \sqrt{( {b})^{2} - 4ac } }{2a} [/tex]
a = 1 b = 0 c = -20
So we have
[tex]x = \frac{ - 0 ± \sqrt{ {0}^{2} - 4(1)( -20)} }{2(1)} \\ \\ x = \frac{± \sqrt{80} }{2} \\ \\ x = \frac{±4 \sqrt{5} }{2} \\ \\ \\ x = ±2 \sqrt{5} \\ \\ \\ x = 2 \sqrt{5} \: \: \: or \: \: \: x = - 2 \sqrt{5} [/tex]
Hope this helps you.
