Need some Algebra homework help...

[jfls43]

I'm trying to work out a solution to the following Algebra problems, can anyone give me some help? I'm terrible with math and your help is greatly appreciated.

Here are the problems:

1. If the signs of the fraction
-a + 2b
2x - y
are changed, what is the equivalent fraction?


2. Reduce the following fraction to its lowest terms.
8a^2m - 32b^2m
4ax + 8bx


3. Find the Algebraic sum of the following: (this is is really hard)
2a + 3b - a - 2b + a^2 + b^2
3a 4b ab

 

[tkhunny]

I'm terrible with math...
(this is is really hard)

The very most help I could give you is to insist that you NEVER talk like this, think like this, or act like this again. If you continue in this way, you WILL fail. Simply stop it. If someone else is saying it, ask them to stop immediately.

There are rules. Learn them and follow them. You have demonstrated already an ability to think. That is what is most required.

1. "If the signs are changed"?? Think about it: If you have 1/2, and you change it to (-1)/(-2) = 1/2, what has been accomplished? (Unfortunately, in this case the question is "bad". I'll tell you why if you ask.)

2. Your task is to find common factors, and then cancel. Nothing else. Factor the numerator and the denominator separately; then look around for common factors.

4ax + 8bx = 4(ax + 2bx) = 4x(a + 2b) -- Be sure you see how to do this.

8a^2m - 32b^2m = 8(a^2m - 4b^2m) = 8m(a^2 - 4b^2) = 8m(a +2b)(a - 2b) -- Be sure you see every step of this. The difference of squares (the last step) is very important.

The Numerator has factors 8, m, a + 2b, and a - 2b
The Denominator has factprs 4, x, and a + 2b

Find the ones in common and get them out. Then you will be done.

3. You already know how to add fractions. Get a common denominator and add up the numerators.

The first fraction has factors 3 and a.
The second fraction has factors 4 and b.
The third fraction has factors a and b.

The least common denominator (LCD) is that denominator which meets the requirements of all three.

The first denominator tells us the LCD needs 3 and a. Great; so far, we have 3a.
The second says the LCD needs 4 and b. Too bad; at this point, we have none of that. So throw it all in. So far, we have 3*a*4*b.
The third says the LCD needs a and b. We already have those, so we're done.

You do the rest.

 

[jfls43]

thanks for the 1st reply

Could you translate what you said into standard english? thanks anyway

 

[stapel]

Could you translate what you said into standard english?

I don't know what your native tongue might be, but the tutor's reply was in "standard English". :shock:

If you're having trouble understanding what was said, then please consider getting help from a friend who is more familiar with the language and who can translate the post into whatever language you better understand.

Thank you!

Eliz.

P.S. Welcome to FreeMathHelp!

 

[jfls43]

I speak english as a native tongue

Your post or reply to my original post didn't really help. I'm struggling with doing this and was hoping you could have written your response in a little easier to understand terms for me.

Let me ask the question this way...

The problem reads: If the signs of the fraction are changed, what fraction is equivalent to the given fraction?

-a+ 2b / 2x - y

I think you can change the sign of the fraction to - , then drop the - in the numerator a - 2b / 2x - y

Is that right?

 

[jfls43]

answer to no. 2...

Your task is to find common factors, and then cancel. Nothing else....

The Numerator has factors 8, m, a + 2b, and a - 2b
The Denominator has factprs 4, x, and a + 2b

Find the ones in common and get them out. Then you will be done.

Is the answer to this one 2am - 4 bm / x ?

 

[morson]

Here's some work on 2. to get you on your way:

\(\displaystyle \frac{8a^2m - 32b^2m}{4ax + 8bx}\ = \frac{8m(a^2 - 4b^2)}{4x(a + 2b)}\ = \frac{8m(a - 2b)(a + 2b)}{4x(a + 2b)}\, x, (a + 2b) \not=\ 0\)

By the way, whether tkhunny's post helped is totally up to you. If you actually attempted to understand what they wrote, then maybe you'd have a different viewpoint. Then again, maybe you did try and just couldn't quite grasp it, in which case you should probably approach your teacher (because if terms like 'numerator' and 'denominator' are troubling you, then that's probably the way to go).

 

[jfls43]

not the same answer as my book

its a multiple choice question, the possible answers are:

2am - 4bm / x
or
2am - 2bm / x
or
2a^2m - 8b^2m / ax + 2bx
or
2a^2m - 8b^2m / a + 2b

why are your answers coming up different?

 

[morson]

Well, I would think the fraction with the "lowest" terms would be \(\displaystyle \frac{2m(a - 2b)}{x}\ provided x, (a + 2b) \not=\ 0\) ? Which is equal to the first of your multiple choices.

 

[pka]

Re: not the same answer as my book

its a multiple choice question, the possible answers are:
why are your answers coming up different?

The answer morson found is in that list of choices.
However, you do not appear to have enough skill to see it.
You are really in trouble if you are expected to be able to do these on your own.
The best advice you have been given is from morson: “Go to your teacher”.
You need some serious help. A forum such as this just is not the way to get that level of help. Please take that advice!

 

[stapel]

Your post or reply to my original post didn't really help.

That may be, but I'm afraid the tutor answered your questions fairly clearly.

It may be that the questions are too poorly framed for you to make sense of them within your context. (We aren't in your class, so we can't know, but this is always, unfortunately, a possibility.) Or it may be that you need more help than we can provide, if the examples, steps, and hints don't make any sense at all to you.

In either case, it would probably be a good idea to have a serious heart-to-heart with your instructor and/or your academic counsellor.

My best wishes to you!

Eliz.