How do you use symbols to make the statement 4_5_2_7 = 107 true?
It is a matter of 'playing' with combinations until you hit on one that works.
If we can use
I had several attempts using factorial to give a higher initial value. These failed. Then I hit upon the idea that we could do this:
Now all we need to do is add the 7. So putting it in the order given we have: