For every column but the one with 0s in it, divide the y over the x
Column2: y/x = 10/2 = 5
Column3: y/x = 35/7 = 5
Column4: y/x = 60/12 = 5
So the equation is y = 5x
The reason why we can't use the 0 column is because 0/0 is undefined. The value of 0/0 is not equal to 0, nor is it equal to 1.
So 5 will go in the box.