Step 1: Variables on the left, constants on the right.
Step 2: Divide the coefficient on the 1st order term by 2, square the result, add that result to both sides of the equation (-4 divided by 2 is -2, -2 squared is 4, so add 4 to each side):
Step 3: Now that we have 'completed the square' by creating a perfect square trinomial on the left, factor it:
Step 4: Take the square root:
Clang! Buzz-Buzz-Buzz! Warning, Will Robinson! We have a negative radicand.
Step 5: Factor the -1 out of the radicand:
Step 6: Use the definition of the imaginary number ,namely