Question 1067318

-10, -7,-4,-1
0,1.5,3,4.5
5,8,12,17
-29,-20.5,-21,-21.5 
I really don't understand how to do these can you help me out please 
<pre>Look at the differences between terms. I'll start you off with the 1st series. You add 3 to the 1st to get the 2nd. 
Same goes for the 2nd to get the 3rd. Based on this, you should be able to find the 5th term.

Do the same for the 2nd series, and you'll get the "hang" of it. Before you know it, you'll have the answers for all 4.