Question 751136
If it is supposed to be -3, -13, -23....then you just need the formula for the nth term of an arithmetic sequence:

{{{a[n]=a[1]+(n-1)*d}}}  Where a sub n is the nth term, a sub 1 is the first term, n is the number of the term you are looking to find and d is the common difference between the terms.  So a sub 1 is -3, n is 100, and d is -10:

{{{a[n]=a[1]+(n-1)*d}}}

{{{a[100]= -3+(100-1)*(-10)}}}

{{{a[100]= -3+(99)*(-10)}}}

{{{a[100]= -3-990}}}

{{{a[100]= -993)}}}