The n^th term of sequence is 8 - 5n. Show that the sequence is an A.P.

a_n = 8 - 5n

a₁ = 8 - 5(1) = 8 - 5 = 3

a₂ = 8 - 5(2) = 8 - 10 = -2

a₃ = 8 - 5(3) = 8 - 15 = -7

a₄ = 8 - 5(4) = 8 - 20 = -12

Sequence = 3, -2, -7, -12………..

In above sequence,

a₂ - a₁ = -2 - 3 = -5

a₃ - a₂ = -7 - (-2) = -5

Hence, the above sequence is an A.P. with common difference = -5.