Algebra

[Kundral]

I'm in grade 9 in Canada so I'm just in junior high... hat I'm asking is this... Can someone help me learn basic high school algebra because I'm very talanted in my current math...

[Crim]

Brother, you just stepped in COMPLETELY the right place. Algebra is damn near my life-blood. How may I help you?

[Kundral]

I want to learn how to do questions with more then one variable...

[Crim]

An example, if you would. (Hell, this sounds like algebra two to me... dun-dun-dun)

Wait, sounds like you're learning Substitution and Elimination, right?

[Kundral]

ok random example...

2x-3y=8
x+2y=4

[Erethzium]

What are you trying to do? Solve for X or Y? Just giving us a problem won't help if you don't tell what you're trying to get out of the problem :P

Sys. of ='s, duh. lol

[Kundral]

2x-3y=8
x+2y=4

Solve for both X and Y

[Crim]

Child, that's a system of equations, listen here.

Equation 2 is almost perfect for the Substitution method.

Subtract 2y from both said of that and you get x = -2y +4

Take that and replace it with the x in equation one; 2(-2y +4) - 3y = 8

Distributive property and solve for y; -4y - 3y + 8 = 8

y = 0

Take that and go to Equation 2; x + 2(0) = 4

Distribute and solve for x; x + 0 = 4

x = 4

Now put both back in equation 1 to check them

2(4) - 3(0) = 8

8 = 8 Therefore, correct

Kundral received Substitution Method *DO-DA-DO*

I'll post Elimination in a minute

EliminaTION!

Equation 2, yet again, is almost perfect for elimination

Multiply Equation 2 by -2 giving you -2x + 4y = -8

You know have that and Equation 1, add the two equations together and you knock out x y = 4

Take that y put it in equation 1, solve for x, take x and y put it in equation 2 to check your work

Kundral received EliminaTION Method *DO-DA-DO*

[Bee]

Best advice I can give you: purchase a Texas Instruments model Ti-83, Ti-84, or Ti-89 graphing calculator.

They're a bit expensive(~$80-$100 when I bought mine), but, it'll save your ass time and time again.

Algebra, Geometry, Calculus, Math Models if you're a dumbass like me, it can do it all! They even have games for them!

Seriously, buy yourself a good graphing calculator. Most schools allow the use of them during class, my old school even provided the entire class with one for use in-class(if you wanted to use one for homework, you had to buy your own, or apply for one from the school).

If money is a problem, you can get a Ti-72 or Ti-73. Older model, not as many features, but, they can still prove vital.

[DragonMasterX]

My calculator could never do such things unfortunately, but now that I look back I'm glad it never did allow me to, or I'd be unable to do such a simplicity compared to the stuff they teach at Math I at college. Then again, I never did need them, I learned Substitution and Elimination really fast. And since we're on the topic, I gotta hand it to you Crim, I wouldn't have been able to explain the two methods with so much patience!