Equation of a sequence

Question

Can you help me find the equation of these sequences? Please include the general equations for both types, a_n

22,42,62,82

2,8,32,128

Answer 1

The first sequence has a common difference of d=20 and the first term is a₁=22, so the general equation to represent this arithmetic sequence would be a_n = a₁+(n-1)d = 22+(n-1)(20)

The second sequence has a common ratio of r=4 and the first term is a₁=2, so the general equation to represent this geometric sequence would be a_n = a₁r^n-1 = 2(4)^n-1

Hope this helped!