Intelligence Contest #15 - Win 100% of the SBD + Free Votes

A new way to win SBD and Votes! Win my new Intelligence Contests!!! I will be posting them everyday at random times and you can win 100% of the SBD this post makes + a vote from me (I got 20 steempower + 180 delegated SP, so over 3 cents per vote.)

I have and will not have copied any of the puzzles I post from other websites. They are unique, so you can try using google, but you ain't gonna find the solution by simply clicking "Search this image on google". Just wanted to make that clear :P

You win if you are the first to comment the correct answer in the comments.

RULES:
-Upvote this post
-Comment your answer
-Do not edit your comment
-1 answer per comment
-No spam

Question

John decided to join in a math contest. He needs to figure out the answer to the following:

22 + 28 + 29 + 3 + 7 = -2407
2 + 3 + 4 + 5 + 6 = -52
99 + 9 + 99 + 9 + 99 = -7821
111 + 11 + 1 + 11 + 111 = 101
69 + 420 + 3 + 17 + 1337 = ?

The + can be anything from these 4: +, -, * and /. (Addition, Substraction, Multiplication and Division).
Your task is to figure out what the ??? is. Because there could be multiple possible answers, please also include what each + should be. That way I can check it easily :)

So a possible answer could be (This is just an example... This is not gonna get you the answer)

3 + 3 + 3 + 3 + 3 = 12
4 + 4 + 4 + 4 + 4 = ?
Answer: ?, because 3 x 3 + 3 + 3 - 3 = 12 and so 4 x 4 + 4 + 4 - 4 = 20

PS: Add your logic! Maybe there are multiple solutions, so if you add your logic, it may be correct!

If you liked this contest, please Upvote(required to win prize), Resteem(not required) & Follow (For more!)