# Question #75fee

Jun 19, 2017

Use ${T}_{n}$ = a(n - 1)d formula

#### Explanation:

FOR AN ARITHMETIC SEQUENCE:
" ${T}_{n}$ " stands for the total number
"a" is the first term
"n" is the term number (eg. if you're looking for the 10th term, n = 10)
"d" is the difference between the terms

In you case,
d = -2
a = -2
So you would plug it in the formula accordingly,

${T}_{n}$ = -2(n - 1) -2

Then use the distributive property,
${T}_{n}$ = -2 (-2n + 2)

And that's the recursive rule for your sequence.

NOTE: the formula given is only for arithmetic sequences, which is a sequence where the difference between the consecutive terms is constant.
Eg.
$- 2 \cdot - 2 = 4$
$4 \cdot - 2 = 8$