Math Problem Statement

3Σ2k + 6 - 1250... the top number is 17 and the bottom is k = 4

Solution

It seems like you're asking to evaluate the sum of a series defined by:

k=417(3(2k)+6)1250\sum_{k=4}^{17} (3(2k) + 6) - 1250

Step 1: Simplify the expression inside the sum

We start by simplifying the expression inside the summation:

3(2k)+6=6k+63(2k) + 6 = 6k + 6

Thus, the summation becomes:

k=417(6k+6)1250\sum_{k=4}^{17} (6k + 6) - 1250

Step 2: Split the summation

We can split the sum into two parts:

k=417(6k+6)=k=4176k+k=4176\sum_{k=4}^{17} (6k + 6) = \sum_{k=4}^{17} 6k + \sum_{k=4}^{17} 6

Step 3: Calculate the first sum

The first part involves a sum of multiples of 6:

k=4176k=6k=417k\sum_{k=4}^{17} 6k = 6 \sum_{k=4}^{17} k

The sum of integers from 4 to 17 can be computed using the formula for the sum of an arithmetic series:

k=417k=n2(a+l)\sum_{k=4}^{17} k = \frac{n}{2} (a + l) where:

  • nn is the number of terms: n=174+1=14n = 17 - 4 + 1 = 14
  • aa is the first term: a=4a = 4
  • ll is the last term: l=17l = 17

Thus:

k=417k=142(4+17)=7×21=147\sum_{k=4}^{17} k = \frac{14}{2} (4 + 17) = 7 \times 21 = 147

Therefore:

6k=417k=6×147=8826 \sum_{k=4}^{17} k = 6 \times 147 = 882

Step 4: Calculate the second sum

Now, the second part involves a sum of constant values (6):

k=4176=6×(174+1)=6×14=84\sum_{k=4}^{17} 6 = 6 \times (17 - 4 + 1) = 6 \times 14 = 84

Step 5: Combine the sums

Now, combine both sums:

k=417(6k+6)=882+84=966\sum_{k=4}^{17} (6k + 6) = 882 + 84 = 966

Step 6: Subtract 1250

Finally, subtract 1250 from the result:

9661250=284966 - 1250 = -284

Final Answer:

The value of the summation is:

284\boxed{-284}

Let me know if you'd like a more detailed breakdown or have any further questions!

Here are some related questions you might find interesting:

  1. How do you sum an arithmetic series?
  2. What is the difference between a finite sum and an infinite series?
  3. How do you evaluate sums with a constant term like k=4176\sum_{k=4}^{17} 6?
  4. What are the general steps to solving summation problems?
  5. How does the distributive property apply in summation problems?

Tip: When working with summations, try to split up complex expressions into simpler parts to make the calculation more manageable!

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Math Problem Analysis

Mathematical Concepts

Summation
Arithmetic Series
Algebra

Formulas

Sum of an arithmetic series: Σk = n/2 (a + l)
Simplification: 3(2k) + 6 = 6k + 6

Theorems

Sum of an arithmetic series

Suitable Grade Level

Grades 9-12