The sum of three consecutive terms of an arithmetic sequence is 27, and the sum of their squares is 293. What is the absolute di

Question

2 years ago

7

fference between the greatest and the least of these three numbers in the arithmetic sequence?
The answer is 10 but I don’t know how to get it

1 answer:

Ber [7] · Answer 1 · 2022-12-07T03:03:57+03:00

The absolute difference between the greatest and the least of these three numbers in the arithmetic sequence is 10.

The sequence is an arithmetic sequence. Therefore,

d = common difference

let

a = centre term

Therefore, the 3 consecutive term will be as follows

a - d, a, a + d

a - d + a + a + d = 27

3a = 27

a = 27 / 3

a = 9

Therefore,

(a-d)² + (a)² + (a + d)² = 293

(a²-2ad+d²) + 9² + (a² + 2ad + d²) = 293

(81 - 18d + d²) + 81 + (81 + 18d + d²) = 293

243 + 2d² = 293

2d² = 50

d² = 50 / 2

d = √25

d = 5

common difference = 5

Therefore, the 3 numbers are as follows

9 - 5 , 9, 9 + 5 = 4, 9, 14

The difference between the greatest and the least of these 3 numbers are as follows:

14 - 4 = 10