Question

The first term ofan Arithmetic sequence is 22and it's last term is 8common differenceis - 2find the number of terms​

Answer 1

8

Explanation:

Given:

U₁ = 22

Uₙ = 8

d = -2

Uₙ = U₁ + (n - 1)d

8 = 22 + (n - 1)(-2)

8 - 22 = -2(n - 1)

n - 1 = -14 ÷ (-2)

n - 1 = 7

n = 7 + 1

= 8