Question

Дано: а1=5 а3=15 Найти: d-?

Answer 1

Ответ: q=5

Пошаговое объяснение:

a3-a1           15-5             10

---------   =  -----------   =   ------- =  5

3-1                3-1                2

Answer 2

To find the common difference (d) in an arithmetic sequence, you can use the formula:

an = a1 + (n-1) * d

where: an is the nth term in the sequence, a1 is the first term in the sequence, and d is the common difference.

In your case, we are given two terms of the sequence:

a1 = 5 (the first term) a3 = 15 (the third term)

Now, we can find the common difference (d) using these values.

Let's plug the given values into the formula for the third term (a3):

a3 = a1 + (3 - 1) * d

15 = 5 + 2 * d

Now, isolate d:

2 * d = 15 - 5

2 * d = 10

d = 10 / 2

d = 5

So, the common difference (d) in the arithmetic sequence is 5.