Irrational................................
Inverse variation:

k is a constant
Use the given information (when x=4 y=4) to find the value of the constant:

Then, the given relationship has the next equation:

Use the equation above to find y when x=2:

Then, when x=2, y=8
The student wrote the wrong operation. "The sum of 5y and 3" translates to 5y+3. And here means addition.