Question

Suppose that in a sequence a2 = 14, a4 = 26, a6 = 38, a8 = 50, and a10 = 62. Which of the following is the explicit formula for the sequence?
1. an = 2n + 6
2. an = 2n + 12
3. an = 6n + 2
4. an = 12n + 2

Answer 1

Seems to be aritmetic
an=a1+d(n-1) is aritmetic
a1=fist term
d=comon difference
n=which term


a4-a2=2d where d is the common difference
26-14=12
12=2d
6=d
so
a2-6=a1
14-6=8

an=8+6(n-1)
expand
an=8+6n-6
an=6n+2
3rd option