What is the n th term for an AP with a common difference of -4.5?

1 Answer

The sequence will be: T_n = a-4.5n+4.5

Explanation:

We know the general equation for nth term of an A.P.series is

T_n =a+(n-1)d

where a is the first term of the series and d is the common difference.

Now for the common difference (d = -4.5 ) the sequence will be:

T_n = a+(n-1)(-4.5)

Simplifying gives: T_n = a-4.5n+4.5

The summation of all the terms will be:

S_n =n/2(2a+(n-1)d) where d is the common difference.

In your question d=-4.5.