Question

⦁ Find the sum of the series . 15 sigma n=1, (2n-1) Show your work

Answer 1

Answer:

225

Step-by-step explanation:

The sum of this series is given by the formula:

$S_n=\frac{n}{2}[2a+(n-1)d]$

Where

S_n is the sum

a is the first term (we get this by plugging in n = 1 into "2n-1", we have 2(1) - 1 = 1)

n is the number of terms (the sum is defined for n = 1 to n = 15, so 15 terms)

d is the common different (the difference is successive terms. Here, 2nd term would be 2(2) - 1 = 3, and first term was 1, so d = 3 -1 = 2)

plugging in the info, we will get the sum:

$S_n=\frac{n}{2}[2a+(n-1)d]\\S_{15}=\frac{15}{2}[2(1)+(15-1)(2)]\\=225$

The sum is 225