Translationally invariant symmetric polynomials as coordinates for N-b
ody problems with identical particles are proposed. It is shown that i
n those coordinates the Calogero and Sutherland N-body Hamiltonians, a
fter appropriate gauge transformations, can be presented as a quadrati
c polynomial in the generators of the algebra sl(N) in finite-dimensio
nal degenerate representation. The exact solvability of these models f
ollows from the existence of the infinite flag of such representation
spaces, preserved by the above Hamiltonians. A connection with Jack po
lynomials is discussed.