Question

if 7 times and 7th term of an ap is equal to 11th term.show that it's 18th term is 0

Answer 1

7(A7 )=11(A11)

7(A+6D)=11( A+10D)

7A+42D=11A+110D

7A-11A = 110D-42D

-4A=68D

A= -17D

PUT VALUE OF A

A18= A+17D

A18=-17 D + 17D

A18 = 0


HOPE IT HELPS

,,,,,,,KANISHQ,,,,,,,

MARK BRAINLIEST

Answer 2

Heyy mate ❤✌✌❤

Here's your Answer...

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7( a7) = a11

=> 7( a + 6d) = 11(a + 10d)

=> 7a + 42d = 11a + 110d

=> 4a - 68d =0

=> a = 68d/4

=> a = 17d.------(1)

Now, a18 = a + 17d ------(2)

From eq 1 and 2.

a18 =0.
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