Y= 1/2(x+4) compare to y = (x-1)^2-3 on graph
< 1 and < 4
< 2 and < 3.
they are the on the opposite sides of an x. in the uk we call them opposite angles.
45+10x = y
$45 -- stays the same no matter what so that's constant.
$10 -- this varies dependent on the number of vaccinations your dog needs, so you'd use a variable to represent the number of vaccinations (in this case i'm using variable "x").
so, for example if your dog needed 7 vaccinations, it would be: 45+10(7) = y -- answer being $115.
there is 7 days in a week so just do:
7 x 8
which is 56 bottles.