Question

2. Without adding, find the sum:
(a) 1 + 3 + 5 + 7 +9​

Answer 1

Step-by-step explanation:

Sn = 5/2[2+4*2]

= 2.5*10

= 25

Answer 2

Answer:

1+3+5+7+9

So,we know that for the sum of odd numbers firstly count the total number then square it

n=5 now, For the sum =n square

5square=25answer