What is the closed linear form of the sequence 5, 7.5, 10, 12.5,
a) an = 5 + 2.5n
b) an = 5 - 2.5n
c) an = 2.5 + 2.5n
d) an = 2.5 - 2.5n

Option C)

Step-by-step explanation:

Note that the sequence increases by a factor of 2.5, that is, each term is the sum of the previous term plus 2.5.

therefore this is an arithmetic sequence with an increase factor d = 2.5

The linear formula for the sequence is:

Where

is the first term of the sequence

So

The answer is the option C)

ANSWER

C)

EXPLANATION

The given sequence is:

5, 7.5, 10, 12.5, 15,...

where

The constant difference is:

The closed linear form is given by;

We substitute the values into the formula to get:

Expand to get;