Please, help me. I'LL GIVE BRAINLIEST.

x = -18

Step-by-step explanation:

To find out what the number is, write an algebraic equation based off the given information and solve for x.

It's given that the sum of a number (represented by the variable x) and 12 -- meaning this part would be written as x + 12 -- equals -6. This would mean the equation would be x + 12 = -6.

Now that you've written an equation, isolate x to find its value. (Just subtract both sides by 12.)

Therefore, x = -18.

12cm

the answer is d