What is the 100th term if the sequence? 5 ,1 ,-3,-7

5 ,1 ,-3,-7  ?  what the dickens is going on?

notice, from 5 to 1, is really -4 units,

from 1 to -3, is -4 units as well, 1 -4 = -3  and so on.

so, to get the next term's value, you simply subtract 4 from the current one, namely -4 is the "common difference".

and we also know the first term is 5, ok... then

Sorry i really need my points