Find the sum of the series.

as per my point to view you can use a L.C.M so you can get the answer or you can try using a exponent way like 5by 1 as n value is 1 so it may give yoh answer

1/12

Step-by-step explanation:

firstly the answer will not be -,because 5^(-n)>7^(-n)

then we try the value for first 2:(2/35)+(24/1225)=94/1225

then we can know for n=<3 the value outcome is too small

and 12×94/1225=1128/1225 and the value is nearly 1/12 and that is the answer.

or need limits to do

answer: the answer is 23

step-by-step explanation:

180

step-by-step explanation: