Since I can't type this correctly, I'ma just put an image.

D:  x = ±

Step-by-step explanation:

Given the equation, x² - 31 = 0:

Start by adding 31 to both sides:

x² - 31 + 31 = 0 + 31

x² = 31

Next, take the square root of both sides:

Since 31 is a prime number for which it has no perfect square as its factor, or there are no other factors that can be simplified using the square root operation, then it means that the final answer will be:

x = ±  

Therefore, the correct answer is Option D)  x = ±

150

step-by-step explanation:

(sorry i'm not typing it again just read the other two explanation sections i just typed it'll be the same.)