if D(r)=a determinant(which is given in the attached picture). then what is sigma(D(r) where r is from 1 to n

we have to apply sigma along first row and then elements of first row becomes n(n+1),n,n^2 respectively then taking n comman and subtract 3rd coloumn in 1st column and then first coloumn and second coloumn will become same so your answer is 0