Question

http://www.lessonsite.com/archivepages/6thGradeMath/6th_Math_Lesson36_Question27.jpg

write a rule for this table

Answer 1

Look to see if the x changes by a certain amount at each step.
In this case, it looks like x goes up by 2 at each step

Now see if y changes by a certain amount at each step.
Y goes down by 4

If you see this kind of pattern, you have a straight line.
you can use any pair of (x,y) numbers to find the equation of the straight line.