Tomorrow is my third day of school, and I've hate to fail my first homework assignment. I tend to make a B average in regular math classes, but I'm still kinda shitty with algebra. My homework is a review of Algebra I stuff, and I barely remember any of it.
Please, help me with these questions, and me love you long time.
1) Solve for x: (x-2) - 2(x+4) = 3(2x-3)
2) Solve for x: 2(x-2) = 3(2x-3)
3) Solve for x: 2x - 5 + 3x - 10 = 90
4) Solve for x: x^2 - 5x - 14 = 0
5) Solve for x: x^2 - 2x - 24 = 0
6) Solve the system: { x + 5y = 17
_________________{ 2x + 3y = 13
7) Solve the system: { 2x + 3y = 5
_________________{ x + 2y = 4
That's the first half of the questions on my assignment. What I aim for is to recall all those systems and formulas that I forgot. Some of you might think I'm a dumbass for not understanding this, but oh well. I spent most of Algebra I in my freshman year having weird conversations with two stoners and I barely passed it, so I seriously gotta learn this.
Alright, first thing you want to do is isolate simplify all of the terms. I'll use problem 1 as an example.
(x-2) - 2(x+4) = 3(2x-3)
x-2 - 2x-8 = 6x - 9
-x - 10 = 6x - 9
Then you get get x on one side
-x - 10 = 6x - 9 (add 9 to each side)
-1 = 7x (divide each side by 7)
-1/7 = x
Any questions?
EDIT: Oh you also have polynomials and systems. Gimme a sec.
So, is that how distribution would usually work? When you have somethign like 2(x+4) you get 2x and 8?
Quote from: coz on August 25, 2009, 02:34:45 PM
So, is that how distribution would usually work? When you have somethign like 2(x+4) you get 2x and 8?
You multiply the number on the outside of the parentheses with each term inside of the parentheses. 2 * x = 2x, and 2 * 4 = 8.
If the number on the outside is negative or has a minus sign in front of it, like this.
1-2(x+4)
The negative carries through, like this.
1 - 2x-8
Quote from: coz on August 25, 2009, 02:23:37 PM
4) Solve for x: x^2 - 5x - 14 = 0
This is a bit trickier. If you remember the FOIL technique, it's basically undoing that. If you don't, it's when you see something like this:
(x+4)(x-8)
and multiplying the terms to get something like you see in the problem. You multiply the Firsts, Outside terms, Inside terms, and Last terms, hence FOIL
F: x * x = x^2
O: x * -8 = -8x
I: 4 * x = 4x
L: 4 * -8 = -32
so
(x+4)(x-8) = x^2 - 8x + 4x - 32 = x^2 - 4x -32
So basically, we're given the end product and we need to go backwards. The problem is:
x^2 - 5x - 14 = 0
Since it's x^2 with no coefficient, we know both sets of parentheses start with x.
(x )(x ) = 0
Now since the last number is 14, we need to find two products of -14 that when added together make -5. In this case, it happens to be -7 and 2. So that's what we fill in the parentheses with.
(x-7)(x+2) = 0
Then, we solve each set of parentheses for 0. We do this because since anything times 0 = 0, if one of these = 0, the equation = 0.
x-7 = 0, x+2 = 0
x = -7, x = 2
Yep, you get two answers, and they're both right. So that's that. Any questions here?
Right, right, I'm starting to get this. I posted a system - how do I do that?
Quote from: coz on August 25, 2009, 02:23:37 PM
6) Solve the system: { x + 5y = 17
_________________{ 2x + 3y = 13
I was getting there. I'm doing these one at a time to make sure you get them. This actually isn't too bad. What you do here is you take one of the equations for x or y. I'll be solving the first equation for x.
x + 5y = 17
x = 17 - 5y
Then you plug that in for x in the second equation
2x + 3y = 13
2(17-5y) + 3y = 13
34 - 10y + 3y = 13
34 - 7y = 13
-7y = -21
7y = 21
y = 3
Then we use that to plug 3 in for y in the first equation
x + 5y = 17
x + 5(3) = 17
x + 15 = 17
x = 2
So, x=2, y=3.
Mk, I tried the other system on my own.
I got:
X = 1.375
Y = .75
Is this correct?
You can test these yourself by plugging your answers back into the original equation.
Sorry but it looks like that's not it.
Then it appears I must rework it.
I'm about done with this homework, thanks!
Jesus Christ, how old are you?
don't be a jackass.
im guessing he's a junior if he took algebra freshman year.
Quote from: Bassir on August 25, 2009, 04:38:53 PM
Jesus Christ, how old are you?
I'm a junior but I've forgotten pretty much everything about algebra. I needed help with all those formulas before I could go figure on my own.
Yeah, that's right, I'm part of the majority of students who make B's in regular math classes.
Quote from: coz on August 25, 2009, 05:12:43 PM
I'm a junior but I've forgotten pretty much everything about algebra. I needed help with all those formulas before I could go figure on my own.
Yeah, that's right, I'm part of the majority of students who make B's in regular math classes.
i got an F on my math final last year
Quote from: RDX on August 25, 2009, 04:40:12 PM
don't be a jackass.
im guessing he's a junior if he took algebra freshman year.
It's ridiculous.
7) x=-2
y=3
Quote from: Travis on August 25, 2009, 05:23:22 PM
i got an F on my math final last year
So did I but that's because it was AB Calc and I didn't need it to graduate so I stopped caring. I still got a 4 on the exam.
Quote from: Man of Popsicle on August 25, 2009, 06:48:53 PM
So did I but that's because it was AB Calc and I didn't need it to graduate so I stopped caring. I still got a 4 on the exam.
I had the easiest AP Calculus teacher. I got an A in the class, and a 5 on the BC exam.
Quote from: Satellite Anthem Icarus on August 25, 2009, 06:49:49 PM
I had the easiest AP Calculus teacher. I got an A in the class, and a 5 on the BC exam.
Yeah but you still suck at geometry LOLOLOLOLOLOLOL
Quote from: Man of Popsicle on August 25, 2009, 07:15:18 PM
Yeah but you still suck at geometry LOLOLOLOLOLOLOL
Felt works hard but fucks up a lot. I think he's good at approaching problems but bad at solving them.
I was pretty good at geometry, I would've made straight A's if I wasn't lazy. My thing about math is that it's my way or the highway. In geometry, I would be told all of these formulas and problem solving methods, but half of the time I wouldn't need them to solve the problem. I was really lazy and got shitty grades on homework, but I aced every test and quiz.
Algebra's different. It's something that requires me to pay attention to my boring and uninteresting teacher and to learn all of these formulas which I seem to disregard because I didn't invent them.
Quote from: Alyssa the Glowing Sole on August 25, 2009, 07:31:46 PM
Felt works hard but fucks up a lot. I think he's good at approaching problems but bad at solving them.
LOL OMG.
also pqqu i need your help.
Proposition: If two lines are perpendicular to a third line, they are parallel to each other.
Show me a counterexample or explain why this is.
Quote from: Man of Popsicle on August 25, 2009, 07:15:18 PM
Yeah but you still suck at geometry LOLOLOLOLOLOLOL
euclidean geometry is useless in real life
Quote from: Satellite Anthem Icarus on August 25, 2009, 08:33:14 PM
LOL OMG.
also pqqu i need your help.
Proposition: If two lines are perpendicular to a third line, they are parallel to each other.
Show me a counterexample or explain why this is.
If the question is
QuoteIf two distinct lines are perpendicular to a third line, they are parallel to each other.
Since each line is 90 degrees rotated to the same perpindicular line (I forget the actual geometric jargon for this), then they are paralell. Same angle of incidence = same line.
If they're not distinct, they could be the same line.
Quote from: Satellite Anthem Icarus on August 25, 2009, 08:40:20 PM
euclidean geometry is useless in real life
Biggest bullshit I've ever heard in my life.
Quote from: Alyssa the Glowing Sole on August 25, 2009, 09:05:38 PM
If the question is
Since each line is 90 degrees rotated to the same perpindicular line (I forget the actual geometric jargon for this), then they are paralell. Same angle of incidence = same line.
If they're not distinct, they could be the same line.
In R
3, the x-axis and the y-axis is perpendicular to the z-axis. However, the x-axis and the y-axis intersect. LOL I FOUND A COUNTEREXAMPLE
math disgusts me
Quote from: Satellite Anthem Icarus on August 25, 2009, 09:10:12 PM
In R3, the x-axis and the y-axis is perpendicular to the z-axis. However, the x-axis and the y-axis intersect. LOL I FOUND A COUNTEREXAMPLE
If I were a gay male I'd want to fuck you
Quote from: Alyssa the Glowing Sole on August 25, 2009, 09:05:57 PM
Biggest bullshit I've ever heard in my life.
2D Euclidean geometry does not apply to real life because life isn't shallow
Quote from: Satellite Anthem Icarus on August 25, 2009, 09:20:33 PM
2D Euclidean geometry does not apply to real life because life isn't shallow
For beings who move across a illusionary but very convincing 2D day to day, I think so.
Quote from: Satellite Anthem Icarus on August 25, 2009, 09:10:12 PM
In R3, the x-axis and the y-axis is perpendicular to the z-axis. However, the x-axis and the y-axis intersect. LOL I FOUND A COUNTEREXAMPLE
LOL NON-EUCLIDIAN SPACES LOL YOU GOT ME
Quote from: Alyssa the Glowing Sole on August 25, 2009, 09:22:18 PM
LOL NON-EUCLIDIAN SPACES LOL YOU GOT ME
omg beth gibbons.
let's live in frappworld so we can live with goldfrapp and friends
Quote from: Satellite Anthem Icarus on August 25, 2009, 09:24:34 PM
omg beth gibbons.
let's live in frappworld so we can live with goldfrapp and friends
Where all lines accidentally outline vaginas.
Quote from: Alyssa the Glowing Sole on August 25, 2009, 09:29:52 PM
Where all lines accidentally outline vaginas.
omglol
i need remedial plane geometry ~_~
Quote from: Alyssa the Glowing Sole on August 25, 2009, 09:36:23 PM
No, you don't.
If I'm going to pursue further mathematics, then I rather remove this roadblock. Why do I suck at geometry?
Quote from: Satellite Anthem Icarus on August 25, 2009, 09:41:42 PM
If I'm going to pursue further mathematics, then I rather remove this roadblock. Why do I suck at geometry?
Because it's not your thing. You're a conceptual learner.
Quote from: Alyssa the Glowing Sole on August 25, 2009, 09:42:31 PM
Because it's not your thing. You're a conceptual learner.
I guess. But it could also be that I forgot the entirety of 9th grade to end the effects of undue emotional trauma. ;_;
Quote from: Satellite Anthem Icarus on August 25, 2009, 09:49:16 PM
I guess. But it could also be that I forgot the entirety of 9th grade to end the effects of undue emotional trauma. ;_;
Err, that could do it.