Solve `x^(2)+27=0`

Explanation

Using the formula for the sum of cubes, factor `x^(3)+27=(x+3)(x^(2)-3x+9)`. By the zero product property, `x+3=0` so x=-3, or `x^(2)-3x+9=0`, which can be solved using the
Quadratic formula: `x=(3+-sqrt(9-36))/(2)=(3+-3isqrt(3))/(2)`. The three roots are `-3,(3+3isqrt(3))/(2)`, and `(3-3isqrt(3))/(2)`.
Higher degree polynomials can also take a quadratic form.