if the sum of the first n positive integers is s , what is the sum of the first n negative even integers , in terms of s ?
answer is c given sum of - 1 - 2 - 3 . . . . . - n = s sum of - 2 , - 4 , - 6 . . . . - 2 n = 2 [ sum ( - 1 - 2 - 3 . . . . n ) ] = 2 s
negate(const_2)