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# Have I done this correctly? watch

1. Common denominator is

Your working out is not wrong but it isn't the best way. Don't expand the denominator!
2. (Original post by Math12345)

Common denominator is
ugh im so confused
3. (Original post by Math12345)

Common denominator is

Your working out is not wrong but it isn't the best way. Don't expand the denominator!
Its just with other questions the video i watched said to do it that way ;/
4. (Original post by junayd1998)
ugh im so confused
For example:

Since the common denominator is 18.

With your question the denominators are x(x+3) and (x+3) so the lowest common denominator is x(x+3).
5. (Original post by junayd1998)
Its just with other questions the video i watched said to do it that way ;/
The question helped you by giving the denominator factorised. You don't need to expand it.

Steps:
1. Find (lowest) common denominator.
2. Cross multiply and expand at the numerator.
3. Combine.

For example:

(where the lowest common denominator is (x+1)(x+2))
6. Try:

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Updated: May 4, 2016
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