We want to solve the equation x² + 16 = 0.

Step 1: Move the constant to the other side of the equation:

x² = -16

Step 2: Take the square root of both sides to solve for x. Since the right side is a negative number, we can break it down into the product of the square root of -1 and the square root of 16:

√x² = √(-1) * √(16)

The square root of -1 is represented by the imaginary unit i, and the square root of 16 is 4:

√x² = i * 4

x = ± 4i

Summary: The solutions to the equation x² + 16 = 0 are two complex numbers: x = 4i and x = -4i. This is achieved by taking the square root of -1 (represented by i) and multiplying it by the square root of 16 (which is 4).

We want to check the solutions to the equation x² + 16 = 0, which are x = 4i and x = -4i.

Step 1: Substitute x = 4i into the original equation:

(4i)² + 16 = 16i² + 16 = -16 + 16 = 0

The left side equals the right side, so x = 4i is a valid solution.

Step 2: Substitute x = -4i into the original equation:

(-4i)² + 16 = 16i² + 16 = -16 + 16 = 0

The left side equals the right side, so x = -4i is also a valid solution.

Summary: By substituting the solutions x = 4i and x = -4i back into the original equation x² + 16 = 0, we have verified that both solutions are correct.


We want to solve the equation x² + a = 0.

Step 1: Move the constant to the other side of the equation:

x² = -a

Step 2: Take the square root of both sides to solve for x. Since the right side is a negative number, we can break it down into the product of the square root of -1 and the square root of a:

√x² = √(-1) * √a

The square root of -1 is represented by the imaginary unit i, and the square root of a is represented by √a:

√x² = i * √a

x = ± i√a

Summary: The solutions to the equation x² + a = 0 are two complex numbers: x = i√a and x = -i√a. This is achieved by taking the square root of -1 (represented by i) and multiplying it by the square root of a.