I have to factor this: 4m-8/4-2m (fraction)

Cwiersema

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May 12, 2007
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4m-8/4-2m (fraction) and I alread got this far 4(m-2)/4-2m what is the factor for the denominator it may be simple but I cant find it.
 
\(\displaystyle \L \frac{{4m - 8}}{{4 - 2m}} = - \frac{{4m - 8}}{{2m - 4}} = - \left( {\frac{4}{2}} \right)\left( {\frac{{m - 2}}{{m - 2}}} \right) = - 2.\)
 
pka said:
\(\displaystyle \L \frac{{4m - 8}}{{4 - 2m}} = - \frac{{4m - 8}}{{2m - 4}} = - \left( {\frac{4}{2}} \right)\left( {\frac{{m - 2}}{{m - 2}}} \right) = - 2.\)
Can you explain please?
 
Cwiersema said:
Can you explain please?
If you indeed need more explanation then you have a very deep problem.
That problem is more than we can address in this sort of forum.
 
The very most basic type of factoring is removing a common factor:

You started with this:

4m - 8
---------
4 - 2m

Remove a common factor of 4 from the two terms of the numerator, and a common factor of 2 from the two terms of the denominator:

4(m - 2)
----------
2(2 - m)

The numerator and denominator have a common factor of 2, which you can divide out. Now you've got this:

2(m - 2)
---------
(2 - m)

Do you see that (m - 2) and (2 - m) are OPPOSITES? And when you divide a number by its oppposite, you always get -1.

So, you've got

2 * [ (m - 2) / (2 - m)]
or
2*-1
or
-2

If this does not make sense to you, you probably should talk to your teacher.
 
Cwiersema said:
what is the factor for the denominator it may be simple but I cant find it.
Um... If you can't see a common factor of "2" between "4" and "2m", then you may want to drop back a bit and review your whole-number multiplication (from grade school). You really will need to know this... a lot. :shock:

Eliz.
 
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