Sum = 79*(79+1)/2 = 79*80/2 = 3160
5050
41
The sum of -1 and -2 is -3.
The sum of 1/8 and 3/8 is 1/2
3
Sum = 79*(79+1)/2 = 79*80/2 = 3160
3
if (n%2==0) sum=n/2*(n+1); else sum=(n+1)/2*n;
87
5050
41
1+2+3+4.....+100 = 101*50= 5050
The sum of -1 and -2 is -3.
The sum of 3x plus 2 and -4 plus 3 is 3x+1 if the equation is (3x+2)+(-4+3). If they are two separate questions, 3x+2 remains as itself while -4+3=-1.
The sum of 2/3 and 1/2 is 1 1/6
81*82/2= 3321