Question

Form a sequence that has two arithmetic means between -1 and 59. HELP PLEASE!!

Answer 1

-1, a, b, 59

and you know that :
a-(-1) = b-a = 59-b

or using explicit formula
\[A_n = A_1 + (n-1)d\]
A_1 = -1
A_4 = 59
solve for d