Find the sum of the 20th term of the Arithmetic progress 16+9+2+(-5)+__________
In this arithmetic sequence, the common difference is -7. To find the nth term of an arithmetic sequence, we can use the formula:
nth term = first term + (n-1) * common difference.
Since we are looking for the 20th term, we plug in n = 20:
20th term = 16 + (20-1) * (-7) = 16 + 19 * (-7) = 16 - 133 = -117.
Therefore, the 20th term is -117.
To find the sum of the 20 terms, we can use the sum of an arithmetic series formula:
Sum = (n/2) * (first term + last term).
In this case, n = 20, first term = 16, and last term = -117. Plugging in these values, we have:
Sum = (20/2) * (16 + (-117)) = 10 * (-101) = -1010.
Therefore, the sum of the 20 terms is -1010.