I am very sorry if this doesnt make sense but i tried to give you an example for the first one so you could figure out the 4 and 5.
If y=12 when x=6, determine y when x=18.
Ok if y=12 and x=6 they add up to 18. So X=6 then you are going to have to times 6 by three to get x to equal 18. That means we have to times y by 3 also which equals 36. We can check this by making sure they are congruent or the same. So if the origanal question said y equals 12 and x equals 6. How do you make sure it's the right answer? What do they have in commmon? Well to get 12 you have to multiply 6 by 2 to get 12. And to get 6 you have to divide 12 by 2. So the common number is 2. So for x to equal 18 we have to figure out is the have something in common, so 18 times 3 equals 36 and if 36 divided by 3 we get 18. So the common number is 3.
