4. Vince nt.
GTFO MY ANSWER.
To find the mean (or average) you first add up the numbers you have. NOTHING 1.88
Sum = 79*(79+1)/2 = 79*80/2 = 3160
98
1 plus 1 = 2
-2
2 plus 2y plus x plus x y = 2 plus3y plus 2x (find how many X's there are and add them together and ten Y's and then single numbers)
(0, 2)
4
-2-5
16 + 20 + 14 = 50 = 12 + 14 +14 + 10
2
if (n%2==0) sum=n/2*(n+1); else sum=(n+1)/2*n;