Question

2. If the first term of an AP is-5 and the common difference is 2, then the sum

of its first 6 terms

a. 0 b. 5 c.6 d. 15 ​

Answer 1

Answer:

Given:

➣$a = -5$

➣$d = 2$

➣$n = 6$

Solution:

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

$S_6 = \dfrac{6}{2} [2(-5) + (6 - 1)2]$

$S_6 = 3[-10 + 2(5)]$

$S_6 = 3(-10 + 10)$

$S_6 = 0$

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