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
Answer:
Points that lie on the same line are called collinear points. If there is no line on which all of the points lie, then they are noncollinear points.
Step-by-step explanation:
I dont have an explanation
Answer:
y = 3
Step-by-step explanation:
Since they both go through 3 for the y-coordinate that means the equation is just y = 3.
The two numbers are -6 and -20
-20 x -6 = 120
-20 + (-6) = -26
28 each book 155-15=140 and then 140÷5=28
