Question

Solve the equation by using the Quadratic Formula.

𝑥^2−6⁢𝑥+21=0

Simplify your solutions. If the solutions are real rational numbers, list from least to greatest separated by a comma. If the solutions are not real numbers, write your answer in the form a ± bi. If the solutions are irrational, write your answer in simplified radical form, using ± to express both solutions.

Answer 1

Use the quadratic formula x = [6 ± sqrt(36 − 84)]/2 = [6 ± sqrt(−48)]/2 = [6 ± 4i√3]/2 = 3 ± 2i√3.

So the solutions are 3 ± 2i√3.