Question

Answer for 23 plz plz plz

Answer 1

Answer:

A₍ₙ₎ = - 74 + (n-1) x 6

Step-by-step explanation:

A₍ₙ₎ = A₍₁₎ + (n-1) x d

A₍₁₈₎ = 28 = A₍₁₎ + 17 x d  ..... (1)

A₍₄₀₎ = 160 = A₍₁₎ + 39 x d  .....(2)

(2)-(1)    132 = 22d

d = 6

A₍₁₎ = 28 - 17 x 6 = -74

formula: A₍ₙ₎ = - 74 + (n-1) x 6