рд╣рд▓ :- рджिрдпा рдЧрдпा рд╣ै a3=15
рдорддрд▓рдм, a+2d =15 ........(i)
рддрдеा S10 =125
(10/2)[2a+(10-1)d]=125
5[2a+9d]=125
[2a+9d]=(125/5)
2a+9d=25 ...........(ii)
рдЕрдм рд╕рдоीрдХрд░рдг (i) рддрдеा (ii) рд╕े,
a+2d =15 ........(i) ×2
2a+9d=25 ...........(ii)×1
2a+4d =30 ........(iii)
2a+9d=25 ........(iv)
рдЕрдм рд╕рдоीрдХрд░рдг (iii) рдоें рд╕े (iv) рдХो рдШрдЯाрдиे рдкрд░,рд╣рдо рдкाрддे рд╣ैं рдХि
2a+4d-(2a+9d) =30-25
⇒2a+4d-2a-9d =5
⇒4d-9d=5
⇒-5d=5
⇒d=5/(-5)
рдпा d =-1
рдлिрд░ рд╕рдоीрдХрд░рдг (i) рдоें d рдХा рдоाрди рд░рдЦрдиे рдкрд░,рд╣рдо рдкाрддे рд╣ै рдХि
a+2×(-1) =15
a -2 =15
a=15+2
a=17
рдЕрддः a10=a+9d
=17+9(-1)
=17-9
=8
Class math exercise 5.3 Q.3(ii) in hindi⇒click here
Class math exercise 5.3 Q.3(iii) in hindi⇒click here
Class math exercise 5.3 Q.3(v) in hindi⇒click here
Class math exercise 5.3 Q.3(vi) in hindi⇒click here
Class math exercise 5.3 Q.3(vii) in hindi⇒click here
Class math exercise 5.3 Q.3(viii) in hindi⇒click here
class 10th math exercise 5.3 question 3(ix) in hindi- click here
