Studying for exams

[Rebellious Eagle]

So, I have a 4-day weekend to study for finals, and I'm only studying for 3 of them, because the other two are pieces of cake. History and Science are pretty easy for me, but the only thing I have trouble studying for is Algebra I...it's easy stuff, but just sitting there and solving problems doesn't really do anything for me, especially since my textbook gives us problems that we don't go over in class. The only things I'm really concerned about are systems of linear equations (I totally forget how to do them) and the stupid quadratic formula (it almost never works for me, even though I do it the right way). Does anyone have any good tips for me on how to brush up on some of these skills? Flunking my finals would really suck. D:

[rubah]

Hate to say it, but practicing them by drilling them over and over is probably the best way. Even though you haven't done the textbook problems in class, teachers can always throw a curve-ball and ask you weirdo stuff.

Systems of linear equations can be solved various ways. On you probably don't need to know is via matrices

Two other ways that you probably do need to know, being in Algebra I are elimination and substitution.

For substitution, solve one equation in terms of one variable, then substitute that into the other equation wherever that variable shows up.

For elimination, multiply by certain factors (can be negative) so that when you add the two (or three) equations together, one of the terms cancels out.

The quadratic equation will be your best friend as long as you make sure to memorize it exactly.
x = (-b ± sqrt(b²-4ac))/2a
where a is the coefficient of the x² term, b the x term, and c the constant (no x).

If you want some real-time help, drop by #eoff sometime, and I'm sure someone (愛 or myself, or others) will be happy to help you out.

[blackmage_nuke]

I think if you have absolutely no idea why you're getting wrong answers then you should look back at basic reasoning behind why the methods you are given would work in the first place. It depends on wheter you prefer to memorize formulae or if you prefer to know the proof behind them.

[Rebellious Eagle]

Ohh, now the linear equations are coming back to me. I hated substitution so much when we were learning it that I just preferred to kinda forget about it. :|
I think I'm okay on the quadratic formula. I just frequently mess up the signs on the -4ac part.
I just need help on this one problem...it was on my math test, and I got it wrong, but I can't figure out why.
5p + 9p^2 = 18, which I converted into 9p^2 + 5p - 18 = 0. From there, I did the quadratic formula, and I got x is approximately 2.09 and -3.09, but they're not the right answers. I wonder what I did wrong there.

[Kirobaito]

1.163, -1.719

OK

A = 9
B = 5
C = -18

So, the quadratic formula is -5 +/- root(5^2-4*9*-18) all divided by 18 (2 * 9).

[-5 +/- root(25+648)] / 18.

[-5 +/- root(673)]/18.

The root of 673 is 25.942.

(-5 + 25.942) / 18 = 20.942/18 = 1.163

(-5 - 25.942) / 18 = -30.942/18 = -1.719

Just find where you're messing up and taking account of it. I think I'm clear enough with every step.

[Rebellious Eagle]

Oh, thanks, I see what I did wrong...I made 2(a) 2(b) instead. o_o'

[Jessweeee♪]

Bah, studying is for squares!

[Rebellious Eagle]

Bah, studying is for squares!

But it's hip to be a square!
Anyway, algebra exams are over...I think I did okay, actually.