It has an infinite amount of solutions.
Explanation:
d-3 = -3+d which can be arranged as: d-3=d-3
Since they are equal to each other, no matter what number you input, your solution will be the same which means that there are an infinite amount of solutions. Let’s put this to the test and put in 5 for d. 5-3=5-3 is 2=2. They are equal to each other which means: infinite solution.