Question

What is the sum of the arithmetic sequence 18 E t=1 (5t-4)

Answer 1

Question:

What is the sum of the arithmetic sequence 18 E t=1 (5t-4)

Answer & Step-by-step explanation:

We have to find the sum of Arithmetic series from t = 1 to t = 18 represented by (5t - 4)

The formula to find the sum of an Arithmetic series when first and the last term is known is:

$S_{n}=\frac{n}{2}(a_{1}+a_{n})$

n = Total number of terms = 18

$a_{1}$ = First Term = 5(1) - 4 = 1

$a_{18}$ = 18th Term = 5(18) - 4 = 86

Using the values in the above formula, we get:

$S_{18}=\frac{18}{2}(1+86)\\S_{18}=9(87)\\ S_{18}=783$

Thus, the sum of 18 terms of the given Arithmetic Series is 783.

Answer 2

The arithmetic sequence is:

$\displaystyle\sum_{t = 1}^{18} (5t - 4)$

The answer is:

783