Question

find the sum of first 7 odd positive integers without actual addition ​

Answer 1

Explanation:

step 1 Address the formula, input parameters & values.

Input parameters & values:

The number series 1, 3, 5, 7, 9, . . . . , 13.

The first term a = 1

The common difference d = 2

Total number of terms n = 7

step 2 apply the input parameter values in the AP formula

Sum = n/2 x (a + Tn)

= 7/2 x (1 + 13)

= (7 x 14)/ 2

= 98/2

1 + 3 + 5 + 7 + 9 + . . . . + 13 = 49

Therefore, 49 is the sum of first 7 odd numbers.