Find the thirtieth term of the following sequence. -6, -4, -2, 0,

So hmm -6, -4, -2, 0?  what the heck is going on?

well, from -6 to -4, is really a +2 "difference", and from -4 to -2 is the same amount.  So to get the next term's value, you simply "add 2", therefore, 2 is the "common difference" in this arithmetic sequence.

let's also notice that -6 is our first fellow.

Yo no me sé esa mala mia