Question

Find the first term of a gp whose common ratio is 5 and sum of first 6 terms is 46872

Answer 1

Step-by-step explanation:

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irst term of a gp whose common ratio is 5 and sum of first 6 terms is 46872.

(a/1-r)=6

a=6(1-r)……….Eq.A

a+ar=9/2

a(1+r)=9/2

Substituting the value of a from Eq.A

6(1-r)(1+r)=9/2

6(1-r^2)=9/2

(1-r^2)=3/4

1/4=r^2

r=1/2 or-1/2

If r=1/2 ,a=3

If r=-1/2,a=9