Question

An=an−1−4 a1=15 to explicit formula

Answer 1

Answer:

$a_n=3n-12$

Step-by-step explanation:

We are given the recursive formula:

$a_n=a_{n-1}-4, a_1=15$

This is the recursive formula for an arithmetic sequence.

The explicit formula for an arithmetic sequence is given by:

$a_n=a_1 + d({n-1} )$

Where d=3 is the common difference.

We plug in this values to get:

$a_n=15 + 3({n-1} )$

We now expand and simplify to get:

$a_n=15 + 3n-3$

We simplify to obtain:

$a_n= 3n-12$