ANSWER
[tex](x + 5i)(x - 5i) = 0 [/tex]
EXPLANATION
The given function is
[tex] {x}^{2} + 25 = 0[/tex]
The zeros of this function are;
[tex]x = \pm5i[/tex]
Or
[tex]x = - 5i \: and \: x = 5i[/tex]
[tex]x + 5i = 0\: and \: x - 5i = 0[/tex]
Hence the factored form is:
[tex](x + 5i)(x - 5i) = 0 [/tex]
If the equation were:
[tex] {x}^{2} - 25 = 0[/tex]
Then the factored form is
[tex](x + 5)(x - 5) = 0 [/tex]