Best Answer
x means everything in algebra. It is a variable, which means that its meaning changes based on context. For example, x could be time, but it could also be cars. x is what all Mathematicians chase after and it is also the greatest tool at their disposal. x is generally called an independent variable because its value determines the output of a function. y, on the other hand, is the result of fooling around with x. It's a dependent variable, which means that y changes when x changes.
Well, what you have to do is find the unit rate for each one of those prices and how you do that is by dividing each price by the downloads
so $6.25 divided by 5= $1.25
and then $17.40 divided by 12= $1.45
so that means the one with $6.25/5 downloads has a better deal!
The axis of symmetry is x = -5
