Question

Find the sum of the first 20th term of a linear sequence 1,5,9,13

Answer 1

Explanation:

The sum of the first 20 terms of a linear sequence can be found using the formula for the sum of an arithmetic series:

S = n/2 * (a1 + a20)

where n = number of terms = 20, a1 = first term = 1, and a20 = 20th term = 1 + 4 * (20 - 1) = 77

Substituting these values, we have:

S = 20/2 * (1 + 77) = 20/2 * 78 = 20 * 39 = 780

So, the sum of the first 20 terms of the sequence 1, 5, 9, 13 is 780.