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#1 2008-09-23 16:39:02

Massood E
Member
Registered: 2008-09-23
Posts: 1

Need Help ASAP Please >>> Compound Fractions

So i need some help with a few problems.  I cant seem to get them solved.  Any help will be greatly appreciated.

1.  (1/x - 1/y) / (x² - y²)

2.  (3a / a²/x-1) / (a/x-1) 

3.  (1/2x-3 - 1/2x+3)  /  (1/2x - 1/2x+3)


Those are the three problems im having trouble with.  Again, any help will be appreciated.

Thank You.

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#2 2008-09-24 06:40:35

mathsyperson
Moderator
Registered: 2005-06-22
Posts: 4,900

Re: Need Help ASAP Please >>> Compound Fractions

1.

Edit: I misread the question, look at the next post for the actual answer to 1.
The numerator has 2 fractions in it, so add them to get only one.

The denominator on the new numerator can jump down, and the denominator can be factorised too.

Finally, cancel out the common factor.


The other two use similar methods. One more thing you might need that I didn't use here is when the denominator is a fraction. The denominator of a denominator can jump up to the numerator instead. So:


Why did the vector cross the road?
It wanted to be normal.

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#3 2008-09-24 17:26:34

Chewy
Member
Registered: 2008-08-07
Posts: 67

Re: Need Help ASAP Please >>> Compound Fractions

This is what I got for # 1:









Testing with random values for x and y, I used  x=2 and y=3 to get:





Plugging my test values into the answer, I get:

Last edited by Chewy (2008-09-30 16:29:00)

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#4 2008-09-26 12:40:38

Chewy
Member
Registered: 2008-08-07
Posts: 67

Re: Need Help ASAP Please >>> Compound Fractions

mathsyperson wrote:

1.

Edit: I misread the question, look at the next post for the actual answer to 1.

I thought that might be the case, Mathsy wink

Masood: For problem # 2, I will work it out to a point, and let you do the rest...

#2)   Simplify the numerator first to make things easier to work out:

Numerator part is ...

    (a in numerator cancels out an a from
in denominator. 

Invert and multiply

with above to get:

This is your numerator.

For the denominator, which is

, invert and multiply with the numerator already obtained to get the fractional expression:

You should be able to simplify from here smile

For Problem # 3:

Look closely at what is going on there. The top expression reduces to 0. The bottom to three, resulting in a fraction of 0/3 = 0.

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