An arithmetic sequence is given by 5, 8, 11,... How do you find the value of d?

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Answer 1 · 2018-07-18T13:45:44

$d = 3$ $color(blue)(d=3)$

The nth term of an arithmetic sequence is given by:

$a + (n - 1) d$ $a+(n-1)d$

Where $a$ $bba$ is the first term, $d$ $bbd$ is the common difference and $n$ $bbn$ is the nth term.

We have:

$a = 5$ $a=5$

looking at the second element, we have:

$5 + (2 - 1) d = 8$ $5+(2-1)d=8$

$5 + d = 8 \Rightarrow d = 3$ $5+d=8=>d=3$

Answer 2 · 2018-07-18T22:49:22

$d = 3$ $d=3$

In an arithmetic sequence, $d$ $d$ is our common difference, or the value we add/subtract to go to the next term.

To get from $5$ $5$ to $8$ $8$ , we can add $3$ $3$ .

To get from $8$ $8$ to $11$ $11$ , we can add $3$ $3$ .

In an arithmetic sequence, we always add or subtract the same amount. We see that to get to the next term, we add $3$ $3$ .

This is our $d$ $d$ .

Hope this helps!