Arithmetic sequences (nth term)

Tick the arithmetic sequences.

In order for a sequence to be arithmetic the relations between their numbers must be the sum of a common ratio, therefore to determine which ones are arithmetic sequence we need to satisfy the following expression:

The expression just mean that the subtraction of consecutive terms should be equal for position in the sequence.

"1, 5, 9, 13...":

Since the expression is valid, then this is a arithmetic sequence.

"6, 10, 15, 21...:

Since the expression is invalid, then this isn't a arithmetic sequence.

"2, 3, 5, 8...:

Since the expression is invalid, then this isn't a arithmetic sequence.

"2, -4, 8, -16...:

Since the expression is invalid, then this isn't a arithmetic sequence.

"-1, 2, 5, 8...:

Since the expression is valid, then this is a arithmetic sequence.

"73, 66, 59, 52...:

Since the expression is valid, then this is a arithmetic sequence.

"6, 1, -4, -9...:

Since the expression is valid, then this is a arithmetic sequence.

"1, 2, 4, 8...:

Since the expression is invalid, then this isn't a arithmetic sequence.

Find the first five terms of the patterns with these nth terms.

For :

(6, 9, 12, 15, 18)

For :

(2,11,20,29,38)

Write down a formula for the nth term of these patterns. The first term is n = 1.

The nth term of any arithmetic sequence is:

Therefore we need to identify r in each sequence.

For (9,15,21,27,33):

For (-2,-8,-14,-20,-26):

it is true

step-by-step explanation:

all the combinations add up i used   calculator