Question

12. Find the sum of the first 10 terms of the sequence (2n-1}.
ANSWERS​

Answer 1

Step-by-step explanation:

n=1 2*1-1=1

n=2. 2*2-1=3

n=3. 2*3-1=5

n=4. 2*4-1=7

keep putting values to n till 10 you will get first ten terms

1,3,5,7,9,11,13,15,17,19

Answer 2

Answer:

The correct answer will be -

The sum of the first 10 terms of the given sequence will be 100.

Step-by-step explanation:

Given in the question -

We have to find the sum of the first 10 terms of the sequence which is (2n-1)

Now we will first find the general sum of n terms of the given sequence -

$= \sum_{n=1}^{n=n} (2n-1)\\\\= 2\sum_{n=1}^{n=n}(n) - \sum_{n=1}^{n=n} (1)\\\\= 2\times \frac{n(n+1)}{2} - n\\\\= n^2+n-n\\\\= n^2$

We got the sum of the first n terms of this sequence will be equal to the square of n.

Now, we have to find the sum of the first 10 terms -

$\sum_{n=1}^{n=10}(2n-1)= 10^2 = 100$

So, the sum of the first 10 terms of the given sequence will be 100.

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