Question

НайтиS10.a1=-6;a4=2.4​

Answer 1

A4=a1+3d=2,4

-6+3d=2,4

3d=8,4

d=8,4/3=2,8

a10=a1+9d=-6+25,2=19,2

S10=((a1+a10)

/2)*10=((-6+19,2)/2)*10=

13,2*5=66

Answer 2

To find the 10th term (S10) in the arithmetic sequence, we first need to determine the common difference (d) between consecutive terms. In an arithmetic sequence, the difference between any two consecutive terms is constant.

We are given two terms of the sequence: a1 = -6 (the first term) a4 = 2.4 (the fourth term)

We can use the formula for the nth term (an) of an arithmetic sequence:

an = a1 + (n - 1) * d

where: an = the nth term a1 = the first term n = the term number d = the common difference

To find the common difference (d), we can use the information from a1 and a4:

a4 = a1 + (4 - 1) * d 2.4 = -6 + 3 * d

Now, solve for d:

2.4 = -6 + 3d 3d = 2.4 + 6 3d = 8.4 d = 8.4 / 3 d = 2.8

Now that we know the common difference (d = 2.8), we can find the 10th term (S10):

S10 = a1 + (10 - 1) * d S10 = -6 + 9 * 2.8 S10 = -6 + 25.2 S10 = 19.2

Therefore, the 10th term (S10) in the arithmetic sequence is 19.2.