Plzz solve..

Let H1, H2 be two skew-symmetric bilinear forms on a finite-dimensional vector space V over R. Prove that there is an invertible linear operator Ton V such that H, (T (x) , T (y)) = H2 (x, y) for all x, y E V if and only if Hi and H2 have the same rank. (Hint: Make use of the structure theorem of skew-symmetric bilinear form.)