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
Step-by-step explanation:
area of circle =πr²
=28.28cm²
hope it helps.
Answer:
Since their corresponding angles are congruent and the corresponding sides are in proportion
Step-by-step explanation:
For ABD,
Sin (B) = (AD ÷ AB) =1
∴ AD = AB
and if AD = AB
⇒ AD = AC (since AD 1 CB).
From triangle ACD,
Sin(C) = (AD ÷ AC)
Since AD = AC , Hence Sin (B) = Sin (C) = 1
Also From definition of similar triangles ABD and ACD are Similar (i.e their corresponding angles are congruent and the corresponding sides are in proportion)
Answer:
34416
Step-by-step explanation:
.72(percentage) × 47800(people)
34416
