Answer:
y = 4 + 5x
Explanation:
You can plug in numbers from the top row (the x's) and times and add to see if you get the corresponding number from the bottom row. This problem is a little mean and tricky because if you check with x=1, all of them work out right. But check with any other x and you will see that only one equation works, the first answer.
You can find "the rule" by looking for a pattern in the rows of numbers. The x goes up by 1, and the y goes up by 5 (if you go left to right on the table) With the 5 on top and 1 on the bottom, y/x, you get 5...that's the 5 that is beside the x in the answer. And if you imagine making one more column on the left side of the table, x=0 and y=4, that's the 4 that stands alone in the answer.