x² - 30x - 10 =0
We are going to use formula
[tex]x= \frac{-b+/- \sqrt{b^{2}-4ac} }{2a}
\\ \\ a= 1, b=-30, c= - 10
\\ \\x= \frac{30+/- \sqrt{(-30)^{2}-4(1)(-10)} }{2}
\\ \\ \frac{30+/- \sqrt{900+40} }{2}= \frac{30+/- \sqrt{940} }{2}= \frac{30+/- \sqrt{235*4} }{2} = 15+/- \sqrt{235}
Answer\ is\ C.[/tex]
