Several trees are possible. Here's one of them:
400
(20 x 20)
((5 x 4) x (5 x 4))
((5 x (2 x 2)) x (5 x (2 x 2)))
400 200,2 100,2,2 50,2,2,2 25,2,2,2,2 5,5,2,2,2,2
Use a factor tree. 400 200,2 100,2,2 50,2,2,2 25,2,2,2,2 5,5,2,2,2,2
1997 is already prime; no tree.
51 3,17
350=2x5x5x7
33 11,3
a prime factorization tree
50 25,2 5,5,2
97 is already prime; no tree.
131 is already prime. No tree.
585 195,3 65,3,3 13,5,3,3
141 = 3 x 47