Programming with Variables.

I never studied Algebra, never took an interest in Maths in school, I was more about Science and hands on hardware, but i've just been accepted to enroll at my school and they're going to be testing my maths skills - eek, so I thought i'd quickly brush up on the basics of Algebra just incase i get asked about it.

So I find the video... basics on Algebra

http://www.youtube.com/watch?v=-voEH-F8qNI

X + 4 = 12

So this is the first example i'm confronted with... um i'm taken back what's the value of x? Surely the compiler will know that at compile time, who cares!

Then i thought, if i saw that in Code, how would i normally work that out? i'd go x = 12 - 4 (x must be 8 then)

he comes up with

x + 4 = 12 x + 4 - 4 = 12 - 4 x = 8

As far as i'm concerned, if i coded like this with a Micro controller i'm going to run out of variables fast so the question how does Algebra affect the programming world, as coders are we already not doing a subtle form Algebra anyway? every time i code a routine which involves numbers, is that not Algebra? i'm confused what's the relationship between coding what's it mostly represent in the mathematics world? because as far as I'm concerned, that guy's a moron, X is a variable so what is x REALLY?

is it an Integer? Float? see my point, maybe Algebra is simply a memory consuming monster Variant and X, Y can be what they want... int x,y,z; x = 10; x = x * 10; what's in X? again THE COMPILE DOES! but, X is 10 before it executes the line x = x * 10; now it's 100, in X, but as a programmer, this comes naturally to me to determine the value of a given variable well i Lie, i don't the compiler does lol... but I'd work it out through logic, can I not apply this to pure Algebra?

Compiler expressions are not algebra. “X+4 = 12” would not compile in any language I’m aware of, and “X = X+1” makes no sense algebraically. Various computer languages over time have attempted to abolish “=” as an assignment operator, because of this very issue.
Likewise, a “variable” means different things in a programming world (where it represents storage) and algebra (where it represents an unknown quantity.)
Algebra pretty much defines the rules that let you re-arrange and solve equations. If you’ve never been exposed to algebra formally (sheesh; we started “some” back in 6th grade), you might find it enlightening. But DON’T try to make every bit of algebra map onto some coding construct…