Answer:
x - y = 2
Explanation:
First of all, you would combine like terms, giving you 4x - 4y + 1 = 9.
Next, subtract the numbers, which gives you 4x - 4y = 8.
Finally, divide both sides by 4, which will come to the conclusion of x - y = 2, the simplest form of which this equation can be broken down to.