To solve this problem:

Let's denote the marks obtained by the two students as $x$ and $y$ (where $x > y$).

1. Relation 1: One student secured 9 marks more than the other: $x = y + 9$

2. Relation 2: The marks of one student constitute 56% of the sum of their marks: $x = 0.56 \times (x + y)$

Step-by-step solution:

1. Substituting $x = y + 9$ into the second equation: $y + 9 = 0.56 \times ((y + 9) + y)$

2. Simplify: $y + 9 = 0.56 \times (2y + 9)$

3. Expand: $y + 9 = 1.12y + 5.04$

4. Bring $y$ terms to one side: [ 9 - 5.