Question

Q3A Complete the following activity.
(1) If nineth term of an A.P. is zero then show that 29* term is double
the 19 term.
Solution :
Formula
= a + (9-1)d
0 - 0 8d
putting-
(-O is given)
Now,
- 18
=&d + 18
100
Form (1) and (II) it is proved that = 2*1​

Answer 1

Step-by-step explanation:

Given

9th term of an A.P= a+(9-1)d = 0

= a+8d =0

2(a+19-1)d = 29

a+18d = 29/2

a+ 18d = 14.5

from equation (1)and(2)

a+8d = 0

a+18d = 14.5.

(-) (-) (-)

-10d =-14.5

d= -14.5/-10

d =1.45

a+8*1.45 = 0

a+11.6 =0

a= -11.6

2(a+18d)= 29

2( -11.6+18*1.45) =29

2(-11.6+26.10)= 29

2(14.50) =29

29 =29.