Question

TWO AP's are given 9. 7. S.... and 24, 21. 18,.. term of both the
progressions are equal then find the value of n and term
​

Answer 1

Answer:

Step-by-step explanation:

First term of 1st ap=9,and common difference=-2

Tn=a+(n-1)d

=>Tn=9+(n-1)(-2)

=>Tn=9-2n+2

=>Tn=11-2n

First term of 2nd ap=24,common difference=-3

Tn=a+(n-1)d

=>Tn=24+(n-1)(-3)

=>Tn=24-3n+3

=>Tn=27-3n

A/Q

11-2n=27-3n

=>-2n+3n=27-11

=>n=16

So the value of n=16

Answer 2

Answer:

9,7,5,. . . .

a = 9

d = 7-9 = -2

an= a+(n-1)*d

an=9+(n-1)*-2

an=9-2n+3

an=12-2n --------------(1)

24,21,18,. . . . . .

a=24

d= 21-24= -3

an= a+(n-1)*d

an= 24+(n-1)*-3

an= 24-3n+3

an= 24-3n -----------------(2)

from-(1)&(2)

12-2n = 24-3n

-2n+3n = 24-12

n = 12