Question

find the middle term of anAP : 20,16,12,........,-176​

Answer 1

Given ÷

AP series 20,16,12............-176

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Concept to find out..

Find Middle term Of Ap ....?????

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Formula used...

$\color{blue} \boxed{an = > a + (n - 1) \times d}$

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Solution...

Ap series ..20,16,12,.....,-176

An = a+(n-1)d

a=> 20

d= a2- A1

d = 16-20

d= -4

an = -176

$an \: = a + (n - 1) \times d \\ \\ - 176 = 20 + (n - 1) \times - 4 \\ \\ - 176 = 20 + ( - 4n + 4) \\ \\ - 176 = 20 - 4n + 4 \\ \\ - 176 = 24 - 4n \\ \\ - 176 - 24 = - 4n \\ \\ - 200 = - 4n \\ \\ n = > \frac{ - 200}{ - 4} \\ \\ \boxed{n = > 100}$

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The middle term will be 100

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*If any case sum is need to find out then it will calculate by following formula.

$\color{skyblue}\boxed{sn = > \frac{n}{2} (2a + (n - 1) \times d)}$

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Hope it's helps you

Answer 2

Step-by-step explanation:

hope this helps you........

please mark my answer as brainlist.....