Arithmetic sequence

Question

write the first 5 terms of arithmetic sequence

an= a n-1-6; a 1 = -20

Answer 1

a0 =-8 -6=-14

a1 =-14-6 =-20

a2 = -20-6 = -26

a3 = -26-6 =-32

a4 = -32-6=-38

a5 =-38-6 = -44

an=an-1 - 6, each term equals the previous term minus 6

Answer 2

a_n = a_n-1 - 6, a₁ = -20

a₁ = -20

a₂ = a₁-6 = -20 - 6 = -26

a₃ = a₂-6 = -26 - 6 = -32

a₄ = a₃-6 = -32 -6 = -38

a₅ = a₄-6 = -38 - 6 = -44

For an arithmetic sequence, each term is the same as: a_n= a₁ + (n-1)d, where d is the difference between each term in the sequence:

a_n = -20 + (n-1)(-6)

a₅ = -20 + (4)(-6) = -20 - 24 = -44