Final answer:
The system of equations in echelon form is underdetermined and has infinitely many solutions in nonnegative integers.
Step-by-step explanation:
The system of equations in echelon form is:
x + 2y + z = 787
y + 3z = 42
From the given information, it can be observed that there are three unknowns (x, y, and z) and only two equations. Therefore, the system is underdetermined and there are infinitely many solutions. In this case, the solutions will be in terms of nonnegative integers.