If `(1.5)^(30)=k` , then the value of `sum_((n=2))^(29)(1.5)^n` , is :

the value of sum(-1)^(n+1)(n)/(5^(n))

If sum_(k=1)^(n)k=210, find the value of sum_(k=1)^(n)k^(2).

If sum_(k=1)^(n)k=45, find the value of sum_(k=1)^(n)k^(3).

If D_(r) = |(r,1,(n(n +1))/(2)),(2r -1,4,n^(2)),(2^(r -1),5,2^(n) -1)| , then the value of sum_(r=1)^(n) D_(r) , is

If D_(r) = |(r,1,(n(n +1))/(2)),(2r -1,4,n^(2)),(2^(r -1),5,2^(n) -1)| , then the value of sum_(r=1)^(n) D_(r) , is

If x^(2)-x+1=0 then the value of sum_(n=1)^(5)[x^(n)+(1)/(x^(n))]^(2) is:

If x^(2)-x+1=0 then the value of sum_(n=1)^(5)(x^(n)+(1)/(x^(n)))^(2) is

The value of sum_(n=1)^oo(-1)^(n+1)(n/(5^n)) equals

The value of sum_(n=1)^oo(-1)^(n+1)(n/(5^n)) equals

The value of sum_(n=1)^oo(-1)^(n+1)(n/(5^n)) equals