Answer:
A. Only Khaled
Explanation:
The teachers equation is:
If a row operation on the teacher's equation results in any of the system of the students' equation then the two systems are equivalent and will have the same solution.
For instance:
Let's maintain the bottom equation and add both equation to replace the top equation:
This results in Khaled's equation:
On the other hand we cannot perform a row operation to obtain Miku's equation