A column of numbers 1, - 3,5, - 7,9,11, - 13. Then the 100th number of this column is

A column of numbers 1, - 3,5, - 7,9,11, - 13. Then the 100th number of this column is

-199
Let's start with the numbers: 1,3,5,7,. 2N-1
Let n = 100, then 2N-1 = 199
Let's look for the law of signs: +, -, +, -
If the odd number is + and the even number is - then the sign is-
So the answer is 100 percent - 199

A column of numbers 1, - 3,5, - 7,9, - 11,13,..., then the 100th number in this column is___

-（2×100-1）=-199

In a column of 3 / 1, 5 / 3, 5 / 7, 7 / 9, 9 / 11, 11 / 13 and so on, the difference between 1 and each number is less than 1 / 1000 from ---

1000, you can list inequality solutions
1-(2n-1)/(2n+1)