P is a polynomial havng n roots (x_i )_(1≤i≤n) with x_i ≠ x_j for i≠ j
find the values of Σ_(k1) ^(k=n) (1/(x−x_k )) and Σ_(k=1) ^n (1/((x−x_k )^2 )) .
I think of a two digit number.The sum of the digits is 9.
When the number is reversed and subtracted from the
original, the result is 45. Find the original number