### Home > MC2 > Chapter 6 > Lesson 6.2.1 > Problem 6-82

Look for any *x*-values of 0 to find some sort of constant. In this case, an *x*-value of 0 equates to a *y*-value of -3, so we can include the -3 value in the rule.

Since subtracting 3 does not give the correct *y*-value for the rest of the table, there are more parts to this rule.

We can now try working backwards to find the other missing parts. If the *y*-value was obtained by subtracting 3 among other things, we can add 3 to the *y*-value and see what other changes took place as well.

Using the *x*-value −2 and *y*-value −7:

Adding 3 to −7 = −4

−4 is two times −2, the *x* -value.

By adding 2*x* to the rule, we get *y* = 2*x* − 3.

Test to see if this rule is correct by substituting in 7 for the *x*-value and see if you get 11 as the *y*-value. If it is, use the rule to fill in the rest of the table. One value has been given to you (when *x* = 4, *y* = 5).