The first term is a(1) = -3 The recursive step is a(n) = a(n-1)+7 meaning "add 7 to each previous term to get the next term". This points us to the common difference d being 7
a1 = -3 d = 7
an = a1 + d(n-1) an = -3 + 7(n-1) an = -3+7n-7 an = 7n-10
Answer: [tex]a_{n} = 7n-10[/tex] (it says an = 7n-10 if the image doesn't show up) Note: the n starts at n = 1