He is at -18 feet because you do -28 - 5 which equals -33 after that you do -33 + 15

This is not possible, as -6 is not equal to -4.
Ten thousand - 10,000
thousand literally just haves 1,000
if the twenty is before the three zeros, it would be 20,000 which is twenty thousand. its the same with other numbers. its super simple!
Answer: (3x^7-5x^5+10x^3-4x^2+1)÷(x^2-18)= 5x^1÷-9
Because there are 26 Letters, there are 25 possibilities for the first letter, and 10 choices for the numbers, so:
25*26*26*10*10*10
Multiply:
650*26*1000
16900*1000
There are 16,900,000 possibilities