A.)Hey, there! If you look at the table below, you can see that the output is always 6 more than the input. This means that the rule for this is . The first one, for example, would be (4) + 6 = 10 because you are substituting for the value of x. The second would be (5) + 6 = 11 and so on.
B.) This problem is designed to trip you up. Notice how it says to write an equation for the cost of the number of razors you buy? It doesn't say anything about finding the monthly fee, which means that the number of razors (x) will be our variable. The equation will look like this: , because even if you don't buy any razors, you still have to pay the $12 monthly fee.
Hope this was helpful. :)