What is the common difference of this arithmetic sequence?

2 ⤊

What is the common difference of this arithmetic sequence?

18, 7, -4, -15

2007-11-27 08:38:57 · 4 answers · asked by Still Doll << 4 in Science & Mathematics ➔ Mathematics

4 answers

Take the difference between the first two terms:
18 - 7 = 11

Double-check by trying the other terms:
7 - (-4) = 11
-4 - (-15) = 11

The common difference is 11.

18 (subtract 11) --> 7
7 (subtract 11) --> -4
-4 (subtract 11) --> -15

2007-11-27 08:41:54 · answer #1 · answered by Puzzling 7 · 1⤊ 0⤋

7-18 = -11
-4-7= -11
-15-(-4) = -11

So the common difference is -11 since the difference between each term and the previous one is the same and it is -11.

2007-11-27 16:46:25 · answer #2 · answered by mulla sadra 3 · 0⤊ 0⤋

-11
18-11=7
7-11=-4 and so on

2007-11-27 16:44:53 · answer #3 · answered by surmy 2 · 0⤊ 0⤋

subtract 11

2007-11-27 16:41:34 · answer #4 · answered by Anonymous · 1⤊ 0⤋