For this case we have the following equation:

To clear the value of and we have the following steps:
1st step:
We subtract 6 on both sides of the equation:

2nd step:
We subtract "y" from both sides of the equation:

3rd step:
We add
to both sides of the equation:

4th step:
We divide between 4 sides of the equation:

Thus, the value of y is 5.
Answer:

Option C