Find Sum of 5k: We need to find the sum of the series given by the expression (5k−87) from k=1 to k=40. We can separate the series into two parts: the sum of 5k and the sum of −87.
Find Sum of −87: First, let's find the sum of the series 5k from k=1 to k=40. This is an arithmetic series with a common difference of 5. The sum of an arithmetic series can be found using the formula S=2n×(a1+an), where n is the number of terms, a1 is the first term, and an is the last term.
Calculate Total Sum: The first term a1 when k=1 is 5(1)=5, and the last term an when k=40 is 5(40)=200. The number of terms n is 40. Plugging these values into the formula gives us S=240×(5+200).
Calculate Total Sum: The first term a1 when k=1 is 5(1)=5, and the last term an when k=40 is 5(40)=200. The number of terms n is 40. Plugging these values into the formula gives us S=240⋅(5+200). Calculating the sum S, we get k=10. This is the sum of the series k=11 from k=1 to k=40.
Calculate Total Sum: The first term a1 when k=1 is 5(1)=5, and the last term an when k=40 is 5(40)=200. The number of terms n is 40. Plugging these values into the formula gives us S=240×(5+200). Calculating the sum S, we get k=10. This is the sum of the series k=11 from k=1 to k=40. Now, let's find the sum of the series k=14 from k=1 to k=40. Since k=14 is a constant, the sum of this series is simply k=14 multiplied by the number of terms, which is 40.
Calculate Total Sum: The first term a1 when k=1 is 5(1)=5, and the last term an when k=40 is 5(40)=200. The number of terms n is 40. Plugging these values into the formula gives us S=240×(5+200). Calculating the sum S, we get k=10. This is the sum of the series k=11 from k=1 to k=40. Now, let's find the sum of the series k=14 from k=1 to k=40. Since k=14 is a constant, the sum of this series is simply k=14 multiplied by the number of terms, which is 40. Calculating the sum of k=14 for 40 terms, we get 5(1)=52. This is the sum of the series k=14 from k=1 to k=40.
Calculate Total Sum: The first term a1 when k=1 is 5(1)=5, and the last term an when k=40 is 5(40)=200. The number of terms n is 40. Plugging these values into the formula gives us S=240×(5+200). Calculating the sum S, we get k=10. This is the sum of the series k=11 from k=1 to k=40. Now, let's find the sum of the series k=14 from k=1 to k=40. Since k=14 is a constant, the sum of this series is simply k=14 multiplied by the number of terms, which is 40. Calculating the sum of k=14 for 40 terms, we get 5(1)=52. This is the sum of the series k=14 from k=1 to k=40. To find the total sum of the original series 5(1)=56 from k=1 to k=40, we add the sum of the series k=11 and the sum of the series k=14. This gives us an1.
Calculate Total Sum: The first term a1 when k=1 is 5(1)=5, and the last term an when k=40 is 5(40)=200. The number of terms n is 40. Plugging these values into the formula gives us S=240×(5+200). Calculating the sum S, we get k=10. This is the sum of the series k=11 from k=1 to k=40. Now, let's find the sum of the series k=14 from k=1 to k=40. Since k=14 is a constant, the sum of this series is simply k=14 multiplied by the number of terms, which is 40. Calculating the sum of k=14 for 40 terms, we get 5(1)=52. This is the sum of the series k=14 from k=1 to k=40. To find the total sum of the original series 5(1)=56 from k=1 to k=40, we add the sum of the series k=11 and the sum of the series k=14. This gives us an1. Calculating the total sum, we get an2. This is the final answer for the sum of the series 5(1)=56 from k=1 to k=40.