Question

Find the sum of the series 5^2+ 7^2+ 9^2+ ... + 39^2​

Answer 1

Answer:

The given sequence is 5, 2, 7, 9, 16, 25, ?

In the given sequence, the first two numbers are given and there after it is sum of the previous two numbers.

Lets say First number is a => a = 5

Second number is b => b = 2

Third number is c => a + b => c = 5 + 2 = 7

Fourth number is d => c + b => 7 + 2 = 9

Fifth number is e => d + c => 9 + 7 = 16

So the series can be written as

5, 2, 7, 9, 16, 25, 41, 66…..