Question

find the sum of 1st even natural number .​

Answer 1

Answer:

Hence, the sum of the first n even natural numbers is n [n + 1].

Answer 2

$Question :-\\ = find the sum of 1st even natural number ?\\Answer :-\\ = the sum of 1^{st} 10 even natural number are :-\\ 2 , 4 , 6 , 8 ,.......\\where ,\\ a = 2 \\ d = 2\\ n = 10\\therefore :-\\ a_{n} = a + ( n + 1 )d\\ = 2 + 9*2\\ = 20\\so,\\ s_{n} = \frac{n}{2} [a +a_{n} ]\\ = 5 [ 2 + 20]\\ = 5 [22]\\ = 110\\\\thank you$