8/9
The sum of the numbers given is 31. 1 + 2 + 4 + 8 + ... + 2n = 2n+1 - 1
It is simply: 1/79
The sum of -1 and -1 is -2.
1+0+3 is the digit sum of 103
if (n%2==0) sum=n/2*(n+1); else sum=(n+1)/2*n;
78 + 1 = 79
8/9
The answer would be positive 3.
the sum of 1 plus 9 is 10 because 1+9
(xn+2-1)/(x2-1)
80
0
3x2 + 2x + 3 + x2 + x + 1 = 4x 2+ 3x + 4
The sum is: 8
The sum is 1511.
The sum of the numbers given is 31. 1 + 2 + 4 + 8 + ... + 2n = 2n+1 - 1