Question

Can someone please help me i dont understand it

Answer 1

An = 12 -8(n-1)

Explanation:

Here, we want to write an explicit rule

The nth term of an arithmetic sequence is;

Tn= a + (n-1)d

d is the common difference which is ;

4-12 = 12-20 = -8

The first term is 12

Substituting these values;

Tn = 20 + (n-1) -8

Tn = 20 -8n + 8

Tn = 28-8n

so, the correct option is;

An = 12 -8(n-1)