Question

Question was provided via image upload.

Explanation:

Step1: Recall one-solution equation rule

For $ax + b = ax + c$, one solution exists only if $b
eq c$.

Step2: Match given equation structure

Given $3x + 8 = 3x + \square$, set $\square
eq 8$.

Step3: Choose valid non-8 value

Any number except 8 works, e.g., 5.

Answer:

Any real number except 8 (example: 5)