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#1 2007-09-10 08:30:38

lightning
Real Member
Registered: 2007-02-26
Posts: 2,060

i want to get a head start on...

...algebra but i'm a beginer and a bad speller so do super easy stuff
so i can shoot up and in to the sky with my maths!
i know JaneFairfax is good at algebra and a lot of people are too so some one help!!!


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#2 2007-09-10 10:23:31

Ricky
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Registered: 2005-12-04
Posts: 3,791

Re: i want to get a head start on...

Here, try this algebra problem:

Let A ≠ 1 be an abelian group with no elements of order 2.  Show that there is a group G containing A such that |G : A| = 2 and Z(G) = 1.

Sorry, I just couldn't resist.


"In the real world, this would be a problem.  But in mathematics, we can just define a place where this problem doesn't exist.  So we'll go ahead and do that now..."

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#3 2007-09-10 18:35:56

Devantè
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Registered: 2006-07-14
Posts: 6,400

Re: i want to get a head start on...

Lightning, algebra is such a wide subject, it covers so many areas of mathematics. It would help us if you told us what topic of algebra you need help on, such as substitution.

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#4 2007-09-10 19:07:21

lightning
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Registered: 2007-02-26
Posts: 2,060

Re: i want to get a head start on...

i don't know any but the easyist would be very nice considering i've never did it before i'm only on level E in maths


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#5 2007-09-10 20:02:02

Identity
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Registered: 2007-04-18
Posts: 934

Re: i want to get a head start on...

Hmmm, so do you know the distributive property, or how to factorise binomials or trinomials? Can you solve linear or quadratic equations yet?

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#6 2007-09-10 22:40:21

landof+
Member
Registered: 2007-03-24
Posts: 131

Re: i want to get a head start on...

lightning, you are in the same boat as me... I haven't have much thought about algebra... I'm interested to learn the same way though.


I shall be on leave until I say so...

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#7 2007-09-10 23:33:17

John E. Franklin
Member
Registered: 2005-08-29
Posts: 3,588

Re: i want to get a head start on...

Here's the difference between two squares in algebra:
    25 - 16 = 9    and   (5 + 4) times (5 - 4) is also 9 times 1 is also 9.
Here's another one:
    (9-1)times(9+1)=80 and   9squared - 1 is also 80.

This is the difference between two squares:
  a*a - b*b = (a + b)*(a-b)

Also the times symbol for multiplying is usually left out, so 7 times 9 would be (7)(9).
Or A times B would be just AB .


igloo myrtilles fourmis

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#8 2007-09-10 23:35:38

landof+
Member
Registered: 2007-03-24
Posts: 131

Re: i want to get a head start on...

And, so I've heard, lets say a 4 digit number FACE
should be like this right(?):
____
FACE


I shall be on leave until I say so...

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#9 2007-09-11 04:19:59

Devantè
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Registered: 2006-07-14
Posts: 6,400

Re: i want to get a head start on...

What level of algebra are you 'at', landof+? Perhaps we can also help you. What area are you looking at? smile

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#10 2007-09-11 05:39:10

lightning
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Registered: 2007-02-26
Posts: 2,060

Re: i want to get a head start on...

Identity wrote:

Hmmm, so do you know the distributive property, or how to factorise binomials or trinomials? Can you solve linear or quadratic equations yet?

i didn't destroy property whatsoever. and no i didn't see a tortoies in any triangle


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#11 2007-09-11 05:50:39

Devantè
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Registered: 2006-07-14
Posts: 6,400

Re: i want to get a head start on...

Identity, Lightning is at Elementary level, eg. At 'starting-school' level. You can't expect him to know anything about binomials and trinomials (he said so himself). But we can teach all of this to him. smile

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#12 2007-09-11 06:05:19

lightning
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Registered: 2007-02-26
Posts: 2,060

Re: i want to get a head start on...

yep and quick and i want to be on top of the tps


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#13 2007-09-11 06:09:08

Devantè
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Registered: 2006-07-14
Posts: 6,400

Re: i want to get a head start on...

Well, what do you know about algebra already?

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#14 2007-09-11 08:51:08

lightning
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Registered: 2007-02-26
Posts: 2,060

Re: i want to get a head start on...

absolutely completly and totally............... nothing

i have three reasons to learn algebra

1. to acctully be on top of the class
2. to get better grades
3. see when i go into a thread(about algebra) i take one look, just one look and i go back and if i learn it i could help people....


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#15 2007-09-12 00:13:02

landof+
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Registered: 2007-03-24
Posts: 131

Re: i want to get a head start on...

same as lightning... All I know (and supposedly lightning, too) is that algebra can be used to manipulate numbers using certain laws in mathematics to achieve an unknown.


I shall be on leave until I say so...

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#16 2007-09-12 06:29:29

lightning
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Registered: 2007-02-26
Posts: 2,060

Re: i want to get a head start on...

well, let us just say.........i don't have a clue what your talking about, i wish did but i don't


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#17 2007-09-12 09:15:20

bossk171
Member
Registered: 2007-07-16
Posts: 305

Re: i want to get a head start on...

Well, a good place to start is:

if

x-3 = 2

what is x?

All we do to "isolate x" or some people say "solve for x" is add 3 to both sides:

x-3+3 = 2+3

x = 5

Now if

a - 2 = 4

what is the value of a?

EDIT: I formatted kinda funny so the equations stand out.

Last edited by bossk171 (2007-09-12 09:16:09)


There are 10 types of people in the world, those who understand binary, those who don't, and those who can use induction.

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#18 2007-09-13 01:24:48

landof+
Member
Registered: 2007-03-24
Posts: 131

Re: i want to get a head start on...

so, we have to eliminate other figures to achieve unknowns?

lightning, we have to solve (or get) things known as unknowns (funny...) and denoted as a letter such as

or
.


I shall be on leave until I say so...

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#19 2007-09-13 05:38:11

Devantè
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Registered: 2006-07-14
Posts: 6,400

Re: i want to get a head start on...

But algebra is used in almost all areas of maths, especially in sets and logarithms. Trigonometry is also a main factor ...

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#20 2007-09-13 08:46:56

lightning
Real Member
Registered: 2007-02-26
Posts: 2,060

Re: i want to get a head start on...

John E. Franklin wrote:

Here's the difference between two squares in algebra:
    25 - 16 = 9    and   (5 + 4) times (5 - 4) is also 9 times 1 is also 9.
Here's another one:
    (9-1)times(9+1)=80 and   9squared - 1 is also 80.

wait i actully get this so (4+4) times (4-4) = 8?
can we start with this type please  cause i think i got it...


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#21 2007-09-13 09:56:24

Daniel123
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Registered: 2007-05-23
Posts: 663

Re: i want to get a head start on...

Actually lightning, no, (4+4) x (4-4) is the same as (8) x (0), which would give you 0. What John was saying is that if you have an algebraic term that is a "square number" minus another "square number", then you can "factorise" by putting the (root of the first square plus the root of the second square) multiplied by the (root of the first square minus the root of the second square), for example:

x² - 16
= (x + 4) (x - 4)

However, to do this you must be able to factorise/expand brackets, which I'm guessing you can't yet? So the best place to start learning algebra is, quite obviously, at the beginning.

So here is a worked example:
If 2 adults and 3 children want to go to the zoo, and it costs x per adult, and y per child, write an algebraic expression for the total cost.

There are 2 adults, so 2 "lots" of x = 2x, and 3 children, so 3 "lots of y" = 3y, so the final answer is:

total cost = 2x + 3y

I'm assuming you know that 2x means "2 times x"? Once you have that, you can then work out the total cost if given values for x and y.

Next you have simplifying, which is basically collecting "like terms" to make it all tidier. For example:

2x + 4x - 8y + 22x - 4x + 18y - 7y +8x
Count up all the x's and all the y's, and express each of them as one term:
= 32x - 3y, which means 32 "lots of x's" minus 3 "lots of y". Note that you cannot mix x's and y's, just as you can't mix apples and oranges if you are counting apples.

There are many websites you can go on that will explain everyting in detail to you, giving you questions and answers.

A good idea would be to go through these http://www.mathsisfun.com/algebra/index.html methodically, moving on to the next one once you fully understand what you have learnt. You can always ask us if you get stuck on something big_smile!

Good luck!

And by the way.. from the way you write I'm guessing you are Scottish? As am i smile

Last edited by Daniel123 (2007-09-13 09:58:20)

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#22 2007-09-13 13:14:44

John E. Franklin
Member
Registered: 2005-08-29
Posts: 3,588

Re: i want to get a head start on...

8times8=64 and 9times7=64-1
10times10=100=9times11+1, so  x times x = (x-1) times (x+1) +1, where x is 10.
5times5=25=6times4+1
3times3=9=8+1=2times4+1.  If x is 3, then x times x = 9, and x minus 1 is 2 and
x plus 1 is 4, and 2 times 4 is 8, and add one more and you get 9.
This is the difference between two squares when one of the squares is one.
1 times 1 is 1, so 1 squared is 1.
2 times 2 is 4, so 2 squared is 4.
3 times 3 is 9, so 3 squared is 9.
(4)(4)=16, so 4^2=16.
4.5 times 4.5 = 20.25 because 4 times 5 is 20, plus 1/4 is 20.25
5.5 times 5.5 = 30.25 because 5 times 6 is 30, plus 1/4 is 30.25
The quarter comes from 1/2 times 1/2.
(5.5 + 1/2) times (5.5 - 1/2) is the same as 6 times 5.
And 5.5 times 5.5 minus 1/4 is also 6 times 5 or 30.
When you multiply (5.5 +1/2) times (5.5 -1/2), you get four parts, and
two of them cancel out each other and add up to zero.
Like say you have (A + B) times (C - D).
Now we can change this and make it look longer.
You get four terms.
A term is a bunch of things multiplied together, like A times C times D.
Okay, so you get 4 terms, and they are:
A times C 
A times (-D)
B times C
B times (-D)
And you add all of those four terms up.


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#23 2007-09-13 19:16:06

lightning
Real Member
Registered: 2007-02-26
Posts: 2,060

Re: i want to get a head start on...

Daniel123 wrote:

So here is a worked example:
If 2 adults and 3 children want to go to the zoo, and it costs x per adult, and y per child, write an algebraic expression for the total cost.

There are 2 adults, so 2 "lots" of x = 2x, and 3 children, so 3 "lots of y" = 3y, so the final answer is:

total cost = 2x + 3y

I'm assuming you know that 2x means "2 times x"? Once you have that, you can then work out the total cost if given values for x and y.


Good luck!

And by the way.. from the way you write I'm guessing you are Scottish? As am i smile

yup! me scottish is the answer =6?


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#24 2007-09-13 19:34:28

Identity
Member
Registered: 2007-04-18
Posts: 934

Re: i want to get a head start on...

You can't figure out the answer unless you know what the numerical values of 'x' and 'y' are.

For example, if the adult ticket cost is $5 and the child ticket cost is $2, then we have x=5 and y=2. If 2 adults and 3 children go to the zoo, we can work out how much it will cost in total. In this case:
Total = 2x+3y
Total = 2×5 + 3×2
Total = $16

'x' and 'y' are variables. This means that you can give them different numerical values, and they will turn out different answers.

Total = 2x+3y            <--- This is an equation. It links together different variables.

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#25 2007-09-14 09:17:45

Daniel123
Member
Registered: 2007-05-23
Posts: 663

Re: i want to get a head start on...

Ok lets start with a very basic definition of algebra...

Algebra is a branch of mathematics in which letters of the alphabet represent unknown numbers. (like in the zoo question). The most common letters used are x and y, but all letters can be used. I will give you an example of a question, and then one for you to do.

If x + 5 = 8, find the value of x.

How to do it:

x + 5 = 8

You need to get the x on its own on one side of the equals sign, and the best way to do that would be to take away the 5.

However, whatever you do to one side of the equals, you must do to the other, or else it would change the outcome of x.

So, if you take away 5 from the left hand side, you must take away 5 from the right hand side.

x + 5 - 5 = 8 - 5

x = 3

So your aim is to remove all the other terms on the side of the x, to get x on its own. To remove them, you do the opposite of the number to both sides i.e if it is +5, you take away 5. Similarly, if it is times 5, you divide both sides by 5.

Once you have practice at it, you will see it more as moving a term across to the other side and, as this happens, it swaps its sign (i.e x5 will move to the other side and become ÷5). But you are best to think of it as doing the same to both sides to isolate the x at first, and your brain will naturally begin to see it the other way in time.

Ok, so here are some for you to try:

Find the value of x:

1. x + 9 = 16
2. x - 4 = 34
3. 2x + 3 = 11 (remember, 2x means 2 times x. HINT: remove the +3 before you remove the 2 from the x).

Last edited by Daniel123 (2007-09-14 09:20:49)

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