Math, asked by ubaidshah340, 6 hours ago

Question 11: -18,A1,A2.A3,4 are in A.P. find 'd' (a)-11/2 (b)2/11 (c) 11/2 (d)none of these​

Answers

Answered by rameshrajput16h
0

Answer:

Given

a

1

+a

2

+a

3

+...+a

q

a

1

+a

2

+a

3

+...+a

p

=

q

2

p

2

2

q

[2a

1

+(q−1)d]

2

p

[2a

1

+(p−1)d]

=

q

2

p

2

2a

1

+(q−1)d

2a

1

+(p−1)d

=

q

p

⇒2a

1

q+(p−1)qd=2a

1

p+(q−1)pd

⇒2a

1

(p−q)=(pq−q−qp+p)d

⇒d=2a

1

So,

a

21

a

6

=

a

1

+20d

a

1

+5d

=

a

1

+40a

1

a

1

+10a

1

=

41a

1

11a

1

=

41

11

Answered by dhanashree5267
0

Answer:

(c)11/2 hope helping you

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