To find a function (rule) for data you first seek to find its rate of change...
dy/dx=(11-5)/(14-8), (5-0)/(8-3)
dy/dx=1, 1 so this is a constant rate of change for the first derivative which means that it is just a line of the form:
y=mx+b and we found above that m, dy/dx, the slope was just one so:
y=x+b, and using any point we can solve for b, the y-intercept, use (3,0)
0=3+b, so b=-3 and the "rule" is:
y=x-3 (the missing point was (7,4))
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This next one you can just look at and see that it increases by one every time x increases by one so again you have a line of the form
y=x+b, using point (3,7) we solve for the y-intercept...
7=3+b, so b=4 and the rule is:
y=x+4 and the missing term was (12,16)
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Uh, actually all of these tables have lines with a slope one... :P so you really only need to find the y-intercepts and find the missing points...
...
y=x+b and using point (5,9)
9=5+b, b=4 and the line is
y=x+4, so the missing point is (14,18)
....
y=x+b and using point (14,16)
16=14+b, so b=2 so the line is:
y=x+2, and the missing term is (6,8)