Respuesta :

Answer:

[tex]a_n = 14-1.5n[/tex]

Step-by-step explanation:

The explicit rule for the arithmetic sequence is given by:

[tex]a_n =a_1+(n-1)d[/tex]          ....[1]

where,

[tex]a_1[/tex] is the first term

d is the common difference and n is the number of terms.

Given sequence:

12.5, 11, 9.5, 8, 6.5, 5 ...

This is an arithmetic sequence.

here, [tex]a_1=12.5[/tex]  and d =- 1.5

Substitute these in [1] we have;

[tex]a_n = 12.5+(n-1)(-1.5)[/tex]

⇒[tex]a_n = 12.5-1.5n+1.5[/tex]

⇒[tex]a_n = 14-1.5n[/tex]

Therefore, the explicit rule for the given sequence is, [tex]a_n = 14-1.5n[/tex]

The explicit rule for the given sequence is [tex]\rm a_n =14-1.5n[/tex].

It is given that the sequence 12.5, 11, 9.5, 8, 6.5, 5 ...

It is required to find the explicit rule for the sequence.

What is a sequence?

It is defined as the systematic way of representing the data that follows a certain rule of arithmetic.

We have an arithmetic sequence:

12.5, 11, 9.5, 8, 6.5, 5 ...

The explicit rule for the above sequence can be given by:

[tex]\rm a_n=a_1+(n-1)d[/tex]   .....(1)

Where [tex]\rm a_1=12.5[/tex]   and

[tex]\rm d= 11.5-12\Rightarrow-1.5[/tex]

Putting these values in the equation (1), we get:

[tex]\rm a_n=12.5+(n-1)\times(-1.5)[/tex]

[tex]\rm a_n = 12.5-1.5n+1.5\\\\\rm a_n =14-1.5n[/tex]

Thus, the explicit rule for the given sequence is [tex]\rm a_n =14-1.5n[/tex].

Learn more about the sequence here:

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