Suppose that the rule is of the form

Where m is the slope and b is the intercept
The slope can be found using the formula

You can take any two consecutive x and y values from the given table.

Similarly,

As you can see, you will end up with the same slope.
Now let us find the intercept b.
Take any x, y coordinates from the table

Now substitute them in the slope-intercept equation.

So the rule is

Verification:
Let us verify whether we got the correct rule or not
Substitute the input x coordinates into the rule and check the outputs y coordinates.

As you can see, we have got the same results therefore, the rule is correct.