Question

in an arithmetic sequence a1=4 and d=8 which term is 428
Show your work

Answer 1

term(n) = a + (n-1)d
428 = 4 + (n-1)(8)
424 = 8n - 8
432 = 8n
n = 54

Draw your conclusion

Answer 2

S8 = 8/2 [2(A1) + (8 - 1)3]

172 = 8/2 [2A1 + (7)3]

172 = 8/2 (2A1 + 21)

344 = 8 (2A1 + 21)

344 = 16A1 + 168

344 - 168 = 16A1



11 = A1