Question

What is the tenth term of an arithmetic sequence with second term 100 and common difference −12?

Answer 1

4 12-100 it’s 20 can you please explain

Answer 2

4

Explanation:

d = -12

a2 = 100

We know the formula for the terms of an arithmetic sequence is

an = a1+d(n-1)

We can find the first term

100 = a1-12(2-1)

100 = a1-12(1)

Add 12 to each side

112 = a1

The first term is 112

Using the formula with n=10

a10 = 112-12(10-1)

a10 = 112 -12(9)

= 112-108

= 4