1+2+3+.........+122=A ∑ n=1 B

Question

Find whats A and whats B?

Answer 1

S_n =n(a₁ + a_n)/2 = A; a_n = a₁ + (n - 1)d; 122 = 1 + 1( n-1); n = 122; B = 122; A = (1 + 122)122/2 = 7503

Answer 2

A = n(n+1)/2 = 122(122+1)/2 = 123(122)/2 = 7503

the sum of every integer from 1 to 122 = 7503

the sum of 1 integer, from 1 to 1 is just 1 = B

Answer 3

A = (122)(123) / 2

B is not adequately defined.