Answer:
The third answer, y = 4x + 1
Explanation:
Let's take the pair x = 2, and y = 9.
We know what x is, and what the result, y, is now.
Let's plug x into the third equation, y = 4x + 1
y = 4 * 2 + 1
y = 8 + 1
y = 9
We already know that y = 9, so this equation is correct.
Hope this helps!
(Let me know if you want to know why it's not any of the others.)