Question

Find n for the sequence for which an = 37, a1 = -13 and d = 5.

Answer 1

The equation for a sequence is
an=a1+(n-1)d
Replace the variable with what you were given you get
37=-13+(n-1)5
Simplify
37=-13+5n-5
Combine like terms
37=5n-18
Reverse operations
55=5n
Simplify
n=11