Question

यदि एक समांतर श्रेणी का 7वाँ तथा 13 वाँ पद क्रमशः 34 तथा
64 है, तो इसका 18वाँ पद है।
(i).87
(ii) 88
(iii) 89
(iv) 90​

Answer 1

Answer:

please send me in English

Answer 2

Answer:

3) 89

Step-by-step explanation:

I'll answer in English

a7= 34

a+6d = 34 ...... equation 1

a13= 64

a+12d = 64 ....... equation 2

subtracting equation 1 from 2

6d = 30

d= 5

from equation 1

a + 6(5) = 34

a= 34-30 = 4

now,

a18 = a+17d

= 4 + 17(5)

= 4 + 85

= 89