`a_k=1/(k(k+1))` for `k=1,2,3,4,...n` then `(sum_(k=1)^n a_k)^2=`

If a_(k)=(1)/(k(k+1)) for k=1,2,3, .. , n, then (sum_(k=1)^(n) a_(k))^(2)=

If a_(k) = (1)/( k(k+1) ) for k= 1,2,3,….n then (sum_(k=1)^(n) a_(k) )=

If a_k=1/(k(k+1)) for k=1 ,2……..,n then prove that (sum_(k=1)^n a_k)^2 =n^2/(n+1)^2

If a_(K)=(1)/(K(K+1)) for K=1, 2, 3....n , then (sum_(K=1)^(n)a_(K))^(2)=

If a_(K)=(1)/(K(K+1)) for K=1, 2, 3....n , then (sum_(K=1)^(n)a_(K))^(2)=

Evaluate : sum_(k=1)^n (2^k+3^(k-1))

Evaluate : sum_(k=1)^n (2^k+3^(k-1))

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

If Delta_(k) = |(k,1,5),(k^(2),2n +1,2n +1),(k^(3),3n^(2),3n +1)|, " then " sum_(k=1)^(n) Delta_(k) is equal to

If Delta_(k) = |(k,1,5),(k^(2),2n +1,2n +1),(k^(3),3n^(2),3n +1)|, " then " sum_(k=1)^(n) Delta_(k) is equal to