Answer:
2
Explanation:
Equivalent question: Find the slope of line going through points (1,-5) and (10,13).
Line points up vertically and subtract. Then put 2nd difference on top of first difference.
(1,-5)
(10,13)
---------'subtracting
-9, -18
So the slope of the line gong through point's (1,-5) and (10,13) is -18/-9=2.
The common difference of an arithmetic sequence whose first term is -5 and whose tenth term is 13 is 2.