Answer:
n(n+1)(n+5)/3
Step-by-step explanation:
there is no value, as we don't know n.
but we can create a summary formula/ function definition :
this is the sum for k = 1 to n of k×(k+3)
k×(k+3) = k² + 3k
so, the overall sum splits into the sum of k² for k=1 to n, and the sum of 3k for k=1 to n.
and the sum of 3k is 3 times the sum of k for k=1 to n.
Σk² for k=1 to n = [n(n+1)(2n+1)]/6
Σk for k=1 to n = n(n+1)/2
3×Σk for k=1 to n = 3×n(n+1)/2
so, we have a function formula
n(n+1)(2n+1)/6 + 3n(n+1)/2 = n(n+1)(2n+1)/6 + 9n(n+1)/6 =
= n(n+1)(2n+1+9)/6 = n(n+1)(2n+10)/6 = n(n+1)(n+5)/3
1. 0.25. This is because if you have -18.75 and then you add 20 to it you would be left with 0.25.
2. -1.25. This is because if you add AM and Noon together you would get that answer.
3. 14.1. If you do 1.43 + 12.67 then you would get that answer.
Answer:
The answer is D.
Step-by-step explanation:
By process of elimination.
Answer:
40
Step-by-step explanation:
5*(20-12) =
5* 8
40
Answer:
928
Step-by-step explanation:
