For this case we must solve the following quadratic equation:
[tex]50-x ^ 2 = 0[/tex]
Subtracting 50 from both sides of the equation we have:
[tex]-x ^ 2 = -50\\x ^ 2 = 50[/tex]
Applying square root to both sides of the equation we have:
[tex]x = \pm \sqrt {50}\\x = \pm \sqrt {25 * 2}\\x = \pm \sqrt {5 ^ 2 * 2}\\x = \pm5 \sqrt {2}[/tex]
We have two real roots:
[tex]x_ {1} = 5 \sqrt {2}\\x_ {2} = - 5 \sqrt {2}[/tex]
ANswer:
[tex]x_ {1} = 5 \sqrt {2}\\x_ {2} = - 5 \sqrt {2}[/tex]