(x - 5i√2)(x +5i√2)
given the roots of a polynomial p(x), say x = a and x = b
then the factors are (x - a)(x - b)
and p(x) is the product of the factors ⇒ p(x) = (x - a)(x - b)
here x² + 50 = 0 ⇒ x² = - 50 → ( set = 0 for roots)
take the square root of both sides
x = ± √-50 = ± √(25 × 2 × -1) = √25 × √2 × √-1 = ± 5i√2
The roots are x = ± 5i√2
thus the factors are ( x - ( - 5i√2)) and (x - (+5i√2))
x² + 50 = (x + 5i√2)(x - 5i√2)