What is the explicit formula for the arithmetic sequence –7.5, –9, –10.5, –12,

the explicit formula for the arithmetic sequence is given by:

where,

is the first term

d is the common difference,

n is the number of terms.

as per the statement:

–7.5, –9, –10.5, –12,

this is an arithmetic sequence with first term

and d = -1.5

since,

-.5) = -9+7.5 = -1.5,

-10.) = -10.5+9 = -1. and so on

substitute these given values we have;

⇒

therefore, the   explicit formula for the arithmetic sequence is,