" If "D_(r)=|[r,n+1,1],[r^(2),2n-1,(2n+1)/(3)],[r^(3),3n+2,(n(n+1))/(2)]," show that "sum_(r=1)^(n)D_(r)=0

If Dr=|[r,n+1,1],[r^2,2n-1,(2n+1)/3],[r^3,3n+2,(n(n+1))/2]|, show that sum_(r=1)^n Dr=0

If Delta_(r)=|(r-1,n,6),((r-1)^(2),2n^(2),4n-2),((r-1)^(3),3n^(3),3n^(2)-3n)| then sum_(r=1)^(n)Delta_(r)=

Let Delta_(r)=|(r-1,n,6),((r-1)^(2),2n^(2),4n-2),((r-1)^(3),3n^(3),3n^(2)-3n)| Show that sum_((r=1)) ^(n) Delta_(r) is constant.

Let Delta_r=|{:(r,2r-1,3r-2),(n/2,n-1,a),((n(n-1))/2,(n-1)^2,1/2(n-1)(3n-4)):}| Show that sum_(r=1)^(n-1)Delta_r=0

If D_(r)=|(r,x,n(n+1)//2),(2r-1,y,n^(2)),(3r-1,z,n(3n+1)//2)| then sum_(r=1)^(n)D_(r)=

Let Delta_r=|[r , x , (n(n+1))/2] , [2r-1 , y , n^2] , [3r-2 , z , (n(3n-1))/2]|dot Show that sum_(r=1)^n Delta_r=0

Let Delta_r=|[r , x , (n(n+1))/2] , [2r-1 , y , n^2] , [3r-2 , z , (n(3n-1))/2]|dot Show that sum_(r=1)^n Delta_r=0

If Delta_(r) = |(1,r,2^(r)),(2,n,n^(2)),(n,(n(n_1))/(2),2^(n+1))| , then the value of sum_(r=1)^(n) Delta_(r) is

If Delta_(r) = |(1,r,2^(r)),(2,n,n^(2)),(n,(n(n+1))/(2),2^(n+1))| , then the value of sum_(r=1)^(n) Delta_(r) is