Question

In an AP, if n=7 , n th term =4, and d=-4,then value of a is 
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Answer 1

Given:-

• n = 7
• n th term = 4
• d = -4

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To find:-

• Value of a.

⠀

Solution:-

★Formula used:-

${\dag}\:{\underline{\boxed{\sf{\purple{a_n = a + (n - 1)d}}}}}$

⠀

$\tt\longmapsto{4 = a + (7 - 1) -4}$

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$\tt\longmapsto{4 = a + 6(-4)}$

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$\tt\longmapsto{4 = a + (-24)}$

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$\tt\longmapsto{a + (-24) = 4}$

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$\tt\longmapsto{a - 24 = 4}$

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$\tt\longmapsto{a = 4 + 24}$

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$\sf\longmapsto{\boxed{\red{a = 28}}}$

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Hence,

• the value of a is 28.

Answer 2

✶⊶⊷⊶⊷❍❍⊶⊷⊶⊷✶✶⊶⊷⊶⊷❍❍⊶⊷⊶⊷✶

To Find :-

Value of a

Given :-

n =7

d = - 4

Tn = 4

Solution :-

Formula :-

│Tn = a + (n - 1) d│

=> 4 = a + (7 - 1) × - 4

=> 4 = a + (6 × - 4)

=> 4 = a + ( - 24)

=> 4 = a - 24

=> a = 4 + 24

=> a = 28

✶⊶⊷⊶⊷❍❍⊶⊷⊶⊷✶✶⊶⊷⊶⊷❍❍⊶⊷⊶⊷✶

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