Question

यदि किसी a.p. के सातवें पद का 7 गुना उसके 11 पद का 11 गुना हो तो उसका 18 पद ज्ञात कीजिए​

Answer 1

Step-by-step explanation:

7th term of AP = a + 6d

11th term of AP = a + 10d

given that

7(a + 6d ) = 11 (a + 10d)

7a + 42d = 11a + 110d

11a + 110d - 7a - 42d = 0

4a + 68d = 0

4(a + 17d) = 0

a + 17d = 0/4=0

18th term = a + 17d

therefore the 18th term = 0

Hope you get your answer