It is asking you to find the sum of k^2 - 1 from k=1 to k=4. Since that is only 4 numbers, calculating the sum by hand wouldn’t be that bad.
(1^2 - 1) + (2^2 - 1) + (3^2 - 1) + (4^2 - 1) = 26
The easier way to find the sum is to use a few simple formulas.
When we have a term that is just a constant c, the formula is c*n.
When we have a variable k, the formula is k*n*(n+1)/2.
When we have a squared variable, the formula is k*n*(n+1)*(2n+1)/6.
In this case, we have a squared variable k^2 and a constant of -1.
So plug in n=4 to the formulas:
4*5*9/6 - 1*4 = 26
The answer is 26
What type of grade and what type of question is tht it looks weird
<em>Note: It seems you may have unintentionally missed adding the answer choices. Thus, I am solving your question in general to give you the idea of how the percentage works, which anyways would solve your query.</em>
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Answer:
Please check the explanation.
Step-by-step explanation:
Given that we have to determine the expressions which are equivalent to 20 percent of 150.
First, we need to determine what actually 20 percent of 150 really brings.
i.e
20% of 150 = 20/100 × 150
= 30
Thus,
20% of 150 = 30
Therefore, any expression that is equivalent to 30 will be included in the answer to this question.
100 / 9
They both equal 11.11
(70/21)^2 * 8^3 * (1/2^9)
