Question 986769
You are told the values are part of an arithmetic sequence. That says that each "next value" in the sequence is one more step size different than the previous value in the sequence. You are given the 5th and 12th entries in the sequence

The 5th sequence value is -10
The 12th sequence value is 18

That says there are 7 steps (12-5)  that result in a difference of 28 (18 - -10)

Thus each step is then 28/7 = 4 greater then the previous step

What is the value at 2?

2-5 = -3. -3 * 4 = -12. So the value at 2 is 12 less than the value at 5. -10-12 = -22

What is the value at 17? 17-12 = 5. 5*4 = 20. 18+20 = 38

you get the idea now?