Answer:
m = 1 and n = 10.
Step-by-step explanation:
I am assuming you mean -8, m , n, 19.
If they are in AP the 4 terms will have a common difference.
19 - (-8) = 19 + 8 = 27.
So the increase over 3 terms (from -8 to 19) is 27 so we have:
27 / 3 = 9
Therefore the common difference is 9 and the A P is
-8, 1, 10, 19.
