Algebra expert needed

[Ski-bum]

No.
2x by 1x is 2x^^2 or two x squared.
2(x + 4)(x - 3) is
2 ( x(x - 3) + 4(x - 3))
= 2 (x^^2 - 3x + 4x - 12)
= 2 (x^^2 + x - 12)
= 2x^^2 + 2x - 24

INVSTOR Geoff's solving is spot on - does it make sense to you to understand and explain the concept to your daughter now? If not, my sequence of working out is slightly different to Geoff's, but comes up with the same answer.

2(x+4)(x-3)
=(2x+8)(x-3)
= 2x^2-6x+8x-24
=2x^2+2x-24

 

[Crabnet]

Dave, it's been about 25 yrs for me, could understand it then, so lost now!

I have a daughter that just finished high school. She would often ask for help with her algebra and other Maths problems. I used to be very proficient at Maths but found that I had forgotten most of it and also the way they approach the problems was a bit different to what I was familiar with. Although it's still essential to show all your working to get full marks.

What I found useful was the Mathsonline website that used to be sponsored by Maccas. They have whiteboard lessons presented by tutors who explain via an audio channel how to tackle these problems.
I would do the lesson as a refresher then run through the method with the daughter.
Unfortunately they now charge an annual fee.
http://www.mathsonline.com.au/

They have a Guest login with sample lessons that gives you an idea of how the tutoring is presented.

 

[D.T.]

INVSTOR Geoff's solving is spot on - does it make sense to you to understand and explain the concept to your daughter now? If not, my sequence of working out is slightly different to Geoff's, but comes up with the same answer.

2(x+4)(x-3)
=(2x+8)(x-3)
= 2x^2-6x+8x-24
=2x^2+2x-24

Yea, this is more similar to the method I'd use, by multiplying the 2 in first.

I remember the crab claw method from then onwards, very difficult to explain in text medium. Basically it was firsts, insides, outsides, lasts, to ensure all pairs were multiplied.

Sorta like this http://i.imgur.com/tISQG.jpg

 

[INVSTOR]

INVSTOR Geoff's solving is spot on - does it make sense to you to understand and explain the concept to your daughter now? If not, my sequence of working out is slightly different to Geoff's, but comes up with the same answer.

2(x+4)(x-3)
=(2x+8)(x-3)
= 2x^2-6x+8x-24
=2x^2+2x-24

Thanks, totally get it now! Was thrown a bit by ^ symbol. My daughter had done some other sums with squared that I wasn't totally getting, but get it now!!

I have a daughter that just finished high school. She would often ask for help with her algebra and other Maths problems. I used to be very proficient at Maths but found that I had forgotten most of it and also the way they approach the problems was a bit different to what I was familiar with. Although it's still essential to show all your working to get full marks.

What I found useful was the Mathsonline website that used to be sponsored by Maccas. They have whiteboard lessons presented by tutors who explain via an audio channel how to tackle these problems.
I would do the lesson as a refresher then run through the method with the daughter.
Unfortunately they now charge an annual fee.
http://www.mathsonline.com.au/

They have a Guest login with sample lessons that gives you an idea of how the tutoring is presented.

Thanks, will take a look!

 

[INVSTOR]

Yea, this is more similar to the method I'd use, by multiplying the 2 in first.

I remember the crab claw method from then onwards, very difficult to explain in text medium. Basically it was firsts, insides, outsides, lasts, to ensure all pairs were multiplied.

Sorta like this http://i.imgur.com/tISQG.jpg

Yes, thanks. My daughter showed me that earlier- so she gets that part! I need a refresher!!

 

[geoffw]

Yea, this is more similar to the method I'd use, by multiplying the 2 in first.

There's three multiplications (the constant "2" and the two expressions in brackets) so the order is unimportant. I did the two bracketed expressions first just to ensure that the constant wasn't multiplied into both bracketed expressions.

I had the symbol for "to the power of" incorrect, I'm sorry. It's just one ^ as has been shown. I'm used to writing that as a superscript.

 

[devank]

Can I confuse all a little?
2(x+4)(x-3)
=2x^2 + 2x - 24
= (x^2 +x^2) + (5x-3x) + (4 -28)
= (x^2+5x+4) + (x^2 -3x-28)
= (x+4)(x+1) + (x-7)(x+4)

 

[D.T.]

Can I confuse all a little?
2(x+4)(x-3)
=2x^2 + 2x - 24
= (x^2 +x^2) + (5x-3x) + (4 -28)
= (x^2+5x+4) + (x^2 -3x-28)
= (x+4)(x+1) + (x-7)(x+3)

Just shuddup

 

[INVSTOR]

There's three multiplications (the constant "2" and the two expressions in brackets) so the order is unimportant. I did the two bracketed expressions first just to ensure that the constant wasn't multiplied into both bracketed expressions.

I had the symbol for "to the power of" incorrect, I'm sorry. It's just one ^ as has been shown. I'm used to writing that as a superscript.

Thanks for your help! I had to take a break from it for a bit as I ended up getting totally confused and had to do some stuff. It did help though! When I clicked on a page you had linked it looked like for a split second there was ^^ before it converted to squared so the penny was starting to drop but I got busy with other stuff and when I reread what you wrote and ski-bums it all made sense!!

 

[Ostraylia]

A great website is Khan Academy. On it, he teaches many things and you can do little quizzes at the end. He breaks done the complexity rather well. It is 100% free, you don't have to sign up to view/do anything. If you want to keep track of your progress though, it is worth signing up.

If I remember correctly, it was actually started out of the need to help his niece whom lived in a different part of the country. So he instructed her via short videos over youtube. It also helped others and he had further requests for further tutorial vids. It has grown since then.

Anyway, it is really worth taking a look at and learning how this all comes together.
This is probably short cutting it for you, but https://www.khanacademy.org/math/al...ing-binomials/v/special-products-of-binomials go to 7:40 in the vid and he explains why the method is used. I found it pretty straight forward.

Otherwise, try starting from the beginning https://www.khanacademy.org/math/algebra where he explains how it came about and why it is used. Quite interesting really.

Good luck.

 

[Angel]

Does your daughter have access to Mathletics on the web? If so you can use its tutorials if she logs you on.

Does she have a school laptop? If so, the textbook will be on the laptop so students dont have to carry bags full of heavy books home each day.

Expand and simplify - I've got to leave for school now and dont have the time to check it, sorry. Yr 9 is pretty much still the same as when I went to school. The Australian yr 8 curriculum is like a foreign language to a Qlder though!

 

[INVSTOR]

Does your daughter have access to Mathletics on the web? If so you can use its tutorials if she logs you on.

Does she have a school laptop? If so, the textbook will be on the laptop so students dont have to carry bags full of heavy books home each day.

Expand and simplify - I've got to leave for school now and dont have the time to check it, sorry. Yr 9 is pretty much still the same as when I went to school. The Australian yr 8 curriculum is like a foreign language to a Qlder though!

Her public Hugh school last year (yr 9) had mathletics and her teacher showed me how to use tutorials. Just found out the high school she is in this year for yr 10 doesn't have mathletics. My experience so far with public high schools in Perth is that they are too poor to have laptop programs, etc. All the public and private high schools in Bris I queried had them, so it seems to be a very different system here.

Thanks for all the advice and links everyone, has been a huge help.

 

[INVSTOR]

This year/school has been quite a stuff up. Had an interview last year and was told daughter could choose to do all these wonderful courses. She arrived first day and they lost her file, forgot to enroll her, and advised she couldn't do the wonderful courses. She couldn't even log into school computers for a week because she wasn't enrolled. Eek! Hopefully I'll get it right with my next choice of school! Rant over!!!

 

[D.T.]

This year/school has been quite a stuff up. Had an interview last year and was told daughter could choose to do all these wonderful courses. She arrived first day and they lost her file, forgot to enroll her, and advised she couldn't do the wonderful courses. She couldn't even log into school computers for a week because she wasn't enrolled. Eek! Hopefully I'll get it right with my next choice of school! Rant over!!!

Typical of any government organisation

 

[vbplease]

Learning this maths is all about following a simple method. Just like tying a shoelace or baking a cake.. You don't learn these things from a computer or tablet so why do you need it for maths? It's just complicating the issue.

I have a feeling your daughter may not be paying attention in class? If the maths teacher is that useless (I suspect not), I'd find a uni-undergrad that can give private tuition cheaply. With a whiteboard and marker.. no computers!!

 

[Dazz]

With a whiteboard and marker.. no computers!!

100% agree.

The students nowadays in high school cling on to their laptops like they are the font of all knowledge.....when in fact the students use them primarily for chatting and social media.

They have very little, if anything, to do with education. How can we be sure ?? Cos what they are taught, the very basics that underpin the branches of science and maths and English and geography haven't changed one iota since the old crusties (including myself) went to school....and none of had computers.

Trying to do maths at school with a computer is a joke, especially when you get up into the higher reaches, where typically all of the numbers disappear. All the flexibility of drawing diagrams and solving puzzles is lost. Even the most basic method (the crab claws referred to above) for expanding brackets can't be easily demonstrated on a computer.

JoeD nailed the answer at the top within 7 minutes.

The only thing that sounded "real" to me was this....

Stop doing your daughters homework. She hasn't written it down properly and that is why you can't work it out.

She gave it to you an hour ago and has been facebooking ever since knowing you are busy trying to solve it

....and to Beanie Girl, it is not BODMAS. You've completely forgotten about indices. The internationally recognised order of mathematical operation is BIMDAS.

Brackets
Indices
Multiplication
Division
Addition
Subtraction

Trying to solve maths problems in any other order and you will arrive at the wrong answer.

I don't have a website link, you do, so you'll probably think yours is correct.

After all, the internet is always right - right ??

 

[BLTN]

Yes! I just can't find any examples where there is a number in front of first bracket and two sets of brackets together

This will always be an issue unless you understand the underlying maths.

The reason why so many people find maths 'hard' is that they try to solve every question by referring to a template question they are familiar with. Maths is about the process, not memorising individual types of questions (there are literally thousands of different ways a question can be written).

So for example, if you understand the process of expanding and simplifying brackets and the ruleset behind it, you can solve any question regardless of what it looks like. If you memorise the way to expand say 2 sets of brackets, you'll be stumped once there is 3 or once there is a number in front or any other variation.

The same rationale applies to pretty much any maths topic.

 

[INVSTOR]

Learning this maths is all about following a simple method. Just like tying a shoelace or baking a cake.. You don't learn these things from a computer or tablet so why do you need it for maths? It's just complicating the issue.

I have a feeling your daughter may not be paying attention in class? If the maths teacher is that useless (I suspect not), I'd find a uni-undergrad that can give private tuition cheaply. With a whiteboard and marker.. no computers!!

100% agree.

The students nowadays in high school cling on to their laptops like they are the font of all knowledge.....when in fact the students use them primarily for chatting and social media.

They have very little, if anything, to do with education. How can we be sure ?? Cos what they are taught, the very basics that underpin the branches of science and maths and English and geography haven't changed one iota since the old crusties (including myself) went to school....and none of had computers.

Trying to do maths at school with a computer is a joke, especially when you get up into the higher reaches, where typically all of the numbers disappear. All the flexibility of drawing diagrams and solving puzzles is lost. Even the most basic method (the crab claws referred to above) for expanding brackets can't be easily demonstrated on a computer.

JoeD nailed the answer at the top within 7 minutes.

The only thing that sounded "real" to me was this....

​

....and to Beanie Girl, it is not BODMAS. You've completely forgotten about indices. The internationally recognised order of mathematical operation is BIMDAS.

Brackets
Indices
Multiplication
Division
Addition
Subtraction

Trying to solve maths problems in any other order and you will arrive at the wrong answer.

I don't have a website link, you do, so you'll probably think yours is correct.

After all, the internet is always right - right ??

No you've got it all wrong.
She spent all Fri night working on one assignment. From 10.00am-to 6.00pm Saturday doing another and Sunday 10.30-5.00 doing her Math. She is the hardest working person I have ever seen. She has never understood Math. Her best year was year 5 where she either got a B or C. She skipped yr 6 completely as we moved interstate so she missed out on some Math curicullam and got behind again and started failing math again. She's an A student in most other subjects and often achieves one of the highest marks for each class. Often her work is used as an example by teachers to show other students. (which doesn't go down well sometimes!!) Sometimes she can't hear well in class as teachers don't control the class. She has recorded how noisy it is- its loud!! I did bring it up in a meeting with deputy principal and she said I'd have to arrange a meeting with head of math. I find the system very strange!

 

[geoffw]

The teaching of mathematics can vary so much on the attitude of the teacher.

My daughter went to one school where every teacher was awful, except the maths teacher. He loved the subject, conveyed his enthusiasm, and communicated well. For the first time she understood and was enthusiastic about the subject.

Unfortunately, because of all the other bad teachers, we changed schools. This time the other teachers were great, but the maths teacher was very poor. She lost interest and understanding.

If private coaching is affordable- even if it's only for a few weeks- do it, but don't be afraid to change tutors if one doesn't work out. Advertise for a uni student- there's plenty around.

Yes, there are websites which should be an adjunct to learning different people learn in different ways, and if one way doesn't work, try another.

Tbh it seems like Dad teaching is not the best way in this area.

 

[Beanie Girl]

....and to Beanie Girl, it is not BODMAS. You've completely forgotten about indices. The internationally recognised order of mathematical operation is BIMDAS.

Brackets
Indices
Multiplication
Division
Addition
Subtraction

Trying to solve maths problems in any other order and you will arrive at the wrong answer.

I don't have a website link, you do, so you'll probably think yours is correct.

After all, the internet is always right - right ??

Dazz, I was a child of 10 when BODMAS was first taught to us. As we did not have to grapple with Indices/Orders(Powers and square roots) yet, the teachers simplified BODMAS to stand for - Brackets Of Division, Multiplication, Addition, Subtraction.

Later as we grew older, we were taught that 'O' stands for Orders (i.e. Powers and Square roots)

http://www.mathsisfun.com/operation-order-bodmas.html

This website explains the concept well, it even refers to your 'Indices'. BODMAS gets called different things in different countries, the website explains this as well.

Note: the only strange name is "Orders". "Exponents" is used in Canada, and so you might prefer "BEDMAS". There is also "Indices" which makes it "BIDMAS". In the US they say "Parentheses" instead of Brackets, so it is "PEMDAS"

BODMAS !

B Brackets first

O Orders (ie Powers and Square Roots, etc.)

DM Division and Multiplication (left-to-right)

AS Addition and Subtraction (left-to-right)