Login

If 7 times the 7th term of an A.P. is equal to 11 times the 11th term,show that 18th term of A.P. is 0.

Let 1st term of AP be 'a',

Let the common difference be 'd',

So,as per question, 7 x 7th term = 11 x 11th term

or, 7 [a+6d]  = 11 [a+10d]

or, 7a+42d = 11a +110d

or, 4a + 68d = 0

or, a + 17d = 0 .......(1)

Now, 18th term = a+17d

or, t18 = 0   { From (1)}

                                            Proved

  • 67
View Full Answer

7A7 = 11 A11 

 7(a+ 6d ) =11(a+ 10d)

7a + 42d = 11a + 110d

 4a + 68d= 0

4(a+ 17d)= 0

 a+ 17d =0

hence A18 = 0   PROVED

  • 26
Here ur answer
  • -4
This is ur answer hope u like!!!

  • 19
Please find your solution below

  • 9
hope it will help you
  • -2
7th term?7=11th term ?11
=>( a+(7-1)d)7=11(a+(11-1)d)
=>7a+42d=11a+110d
=>4a+68d=0
=>a+17d=0
=>a+(18-1)d
=>18th term =0
Proved
  • 2
7 times 7 the term of AP

  • 4
Hsjsjks
 
  • -2
Hhs
  • -2
Let 'a' be the first term and 'd' be the common difference of the given AP.

           7th term of the AP = a + (7-1)d= a+6d
​          11th term of the AP = a = (11-1)d=a+10d
​           18th term of the AP= a +(18-1)d = a +17d      
​             7(a+6d)=11(a+10d)
             7a+42d=11a+110d
​             11a-7a+110d-42d=0
             4a+68d=0
             4(a+17d)=0
               a +17d=0
     Therefore 18th term of AP is equal to zero.
                
  • 3
இந்த கணக்கு ரோம்பவே கஸ்டம்
  • -1
Thanku very much
  • 3
7A7 = 11 A11 7(a+ 6d ) =11(a+ 10d) 7a + 42d = 11a + 110d 4a + 68d= 0 4(a+ 17d)= 0 a+ 17d =0 hence A18 = 0 PROVED
  • 0
Please find this answer

  • 0
Hope it works ??
Cheers ??

  • 0
Please find this answer

  • 0
This is the answer

  • 0
Here is the answer :-

  • 0
Please find this answer

  • 0
Solved

  • 0
Please find this answer

  • 0
Please find this answer

  • 0
Please find this answer

  • 0
Ueoemwhs
  • 0
Hy ebbsueosof Ali sk JC do KBC dj kg DJ ja cm kit DJ xx tu na
  • 0
Twiwiehjdksbdjsmdbdkdbfbjdod svsnsbs
Snsksbsgsms
A.sksnsbjsms
Sbshekmabajemebsejenndbdke
Hsmskgaks
S
Shs bske.ejemd.dbsjs.sns
  • 0
Please find this answer

  • 0
Answer!!
  • 0
Answer!!

Let 1st term of AP be 'a',

Let the common difference be 'd',

So,as per question, 7 x 7th term = 11 x 11th term

or, 7 [a+6d] ?= 11 [a+10d]

or, 7a+42d = 11a +110d

or, 4a + 68d = 0

or, a + 17d = 0 .......(1)

Now, 18th term = a+17d

or, t18?= 0 ? { From (1)}

? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ??Proved
  • 0
What are you looking for?