Question

For what value of n, the nth term of the following two A.P.s are equal?

23, 25, 27, 29,...................... and -17, -10, 3, 4, ..................

Answer 1

An = an
A +(n-1)D = a+(n-1)d
23 +(n-1)2 = -17 +(n-1)


it is wrong a.p. the second one

Answer 2

Answer:

Step-by-step explanation:

23, 25, 27, 29

a = 23, d = a2-a1

d = 25-23

d = 2

an = a+( n-1 ) d

= 23+( n-1 ) 2

= 23+2n-2

an= 21+2n ____ ( 1 )

-17, -10, 3, 4

a = -17, d = a2-a1

= -10-( -17 )

= -10+17

= 7

an = a+( n-1 ) d

= -17+( n-1 ) 7

= -17+7n-7

an = -24+7n _______ (2 )

( 1 ) = ( 2 )

21+2n = -24+7n

21+24 = 7n-2n

45 = 5n

45/5 = n

9 = n

Hope it helps you