Question

пожалуйста помогите c арифметической прогрессией. а9=6, найти S17-?

Answer 1

s17=(a1+a17)/2*17=(a9+a9)/2*17=(6+6)/2*17=6*17=102

Answer 2

Arithmetic Progression and Finding the Sum of Terms

An arithmetic progression is a sequence of numbers in which the difference between any two consecutive terms is constant. The formula to find the nth term of an arithmetic progression is given by:

a_n = a₁ + (n-1)d

Where: - a_n is the nth term - a₁ is the first term - n is the term number - d is the common difference

To find the sum of the first n terms of an arithmetic progression, the formula is:

S_n = n/2 * (a₁ + a_n)

Where: - S_n is the sum of the first n terms - n is the number of terms - a₁ is the first term - a_n is the nth term

Finding the Sum of Terms in the Arithmetic Progression

Given that a₉ = 6, we can use the formula for the nth term to find the value of a₁ and d. Then, we can use the formula for the sum of terms to find S₁₇.

Using the formula for the nth term: a₉ = a₁ + (9-1)d 6 = a₁ + 8d

We also know that a₉ = a₁ + 8d = 6.

This gives us one equation with two unknowns. To solve for a₁ and d, we need another equation. Without the value of a₁ or d, we cannot directly find S₁₇.

If you have the values of a₁ and d, or any additional information, please provide them so we can proceed with finding S₁₇