only one anwser

To solve the equation \(-x^2 - 3x = 5 - 3x\), we first simplify it:

1. Move all terms to one side: \(-x^2 - 3x - 5 + 3x = 0\) \(-x^2 - 5 = 0\)

2. Rearrange: \(-x^2 = 5\)

3. Divide by -1: \(x^2 = -5\)

4. Take the square root: \(x = \pm \sqrt{-5}\)

5. Express using the imaginary unit \(i\): \(x = \pm i \sqrt{5}\)

Thus, the answer is:

\(\pm i \sqrt{5}\)