Math Problem Statement

Use summation formulas to evaluate the sum: sum from k equals 1 to 26 of left parenthesis 4 k squared minus 19 k plus 7 right parenthesis.

sum from k equals 1 to 26 of left parenthesis 4 k squared minus 19 k plus 7 right parenthesis equals 31480

sum from k equals 1 to 26 of left parenthesis 4 k squared minus 19 k plus 7 right parenthesis equals 18317

sum from k equals 1 to 26 of left parenthesis 4 k squared minus 19 k plus 7 right parenthesis equals 31655

sum from k equals 1 to 26 of left parenthesis 4 k squared minus 19 k plus 7 right parenthesis equals 18142

Solution

To evaluate this summation using summation formulas, we can break it down and use known summation formulas for kk, k2k^2, and constants. The expression is:

k=126(4k219k+7)\sum_{k=1}^{26} (4k^2 - 19k + 7)

This can be rewritten as:

4k=126k219k=126k+k=12674 \sum_{k=1}^{26} k^2 - 19 \sum_{k=1}^{26} k + \sum_{k=1}^{26} 7

We'll evaluate each of these components separately.

Step 1: Sum of k2k^2 Terms

The formula for the sum of squares, k=1nk2\sum_{k=1}^n k^2, is: k=1nk2=n(n+1)(2n+1)6\sum_{k=1}^{n} k^2 = \frac{n(n+1)(2n+1)}{6} For n=26n = 26: k=126k2=26×27×536=6201\sum_{k=1}^{26} k^2 = \frac{26 \times 27 \times 53}{6} = 6201 Then, 4k=126k2=4×6201=248044 \sum_{k=1}^{26} k^2 = 4 \times 6201 = 24804

Step 2: Sum of kk Terms

The formula for the sum of integers, k=1nk\sum_{k=1}^n k, is: k=1nk=n(n+1)2\sum_{k=1}^{n} k = \frac{n(n+1)}{2} For n=26n = 26: k=126k=26×272=351\sum_{k=1}^{26} k = \frac{26 \times 27}{2} = 351 Then, 19k=126k=19×351=6669-19 \sum_{k=1}^{26} k = -19 \times 351 = -6669

Step 3: Sum of Constant Terms

Since 7 is a constant, the sum of 26 terms of 7 is: k=1267=7×26=182\sum_{k=1}^{26} 7 = 7 \times 26 = 182

Step 4: Combine Results

Now, we add the three parts together: 4k=126k219k=126k+k=1267=248046669+182=183174 \sum_{k=1}^{26} k^2 - 19 \sum_{k=1}^{26} k + \sum_{k=1}^{26} 7 = 24804 - 6669 + 182 = 18317

Final Answer

The correct answer is: k=126(4k219k+7)=18317\sum_{k=1}^{26} (4k^2 - 19k + 7) = 18317


Do you want more details on any of the steps or have any questions?

Related Questions

  1. How can the sum of squares formula be derived?
  2. What is the summation formula for k3k^3 and when is it useful?
  3. Can summation formulas be applied to non-polynomial functions?
  4. How can we generalize this approach for any quadratic polynomial?
  5. What is the difference between arithmetic and geometric summation?

Tip:

When summing expressions with k2k^2 or k3k^3 terms, always break down the expression into simpler parts and use known formulas to simplify computation.

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Math Problem Analysis

Mathematical Concepts

Summation
Quadratic Expressions
Series

Formulas

Sum of k terms: \( \sum_{k=1}^n k = \frac{n(n+1)}{2} \)
Sum of k squared terms: \( \sum_{k=1}^n k^2 = \frac{n(n+1)(2n+1)}{6} \)

Theorems

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Suitable Grade Level

Grades 10-12