The 10th sum of the sequence: 3, 5, 7, 9, .... is ...

The 40th term of the sequence 7, 5, 3, 1, … is …

The first term of an arithmetic sequence is 5 and the difference = 6, the 10th term of the sequence The arithmetic is...

Of an arithmetic sequence, the third term is 36, the sum of the fifth and seventh terms is 144. The sum of the first ten terms of the series is….

The formula for the nth term of the sequence 5, –2, –9, –16, … is…

From an arithmetic series it is known that U3 = 13 and U7 = 29. The total of twenty-five terms The first in the series is...

It is known that in an arithmetic sequence the first term is 4 and the 20th term is 61. Determine the difference between the arithmetic series!

The fourth and seventh terms of an arithmetic sequence are consecutive are 17 and 29. The 25th term of the sequence is .

In a performance hall, chairs are arranged with the front row consisting of 12 chairs, the second row contains 14 seats, the third row contains 16 seats, and so on. The number of seats on the 20th row is