Question

Factor the expression over the complex numbers.

x2+25

Answer 1

$Use\\\\a^2-b^2=(a-b)(a+b)\\\\i=\sqrt{-1}\to i^2=-1\\------------------------\\\\x^2+25=x^2+5^2=x^2-(-5^2)=x^2-(5i)^2\\\\\boxed{x^2+25=(x-5i)(x+5i)}$