Perform the indicated operation: 2/m-n^2 + 1/n^2-m

Helen

Junior Member
Joined
Oct 28, 2007
Messages
106
2
______ +
m-n^2

1
______
n^2-m



Can you tell me if my answer is correct?

3
______
m-n^2
 
Re: Perform the indicated operation.

No, BUT quite close: yer sure a fast learner!
Hint: your denominator m-n^2 is correct.

By the way, your expression can be posted this way:
2 / (m - n^2) + 1 / (n^2 - m)
 
Re: Perform the indicated operation.

Denis said:
By the way, your expression can be posted this way:
2 / (m - n^2) + 1 / (n^2 - m)

Or better yet...

(2 / (m - n^2)) + (1 / (n^2 - m))


remember:

\(\displaystyle \L \frac{a}{b} + \frac{c}{d} = \frac{ad + cb}{bd}\)

So for your sum of two rationals:

\(\displaystyle \L \frac{2}{m - n^2} + \frac{1}{n^2 - m}\)

= \(\displaystyle \L \frac{2(n^2-m) + (m-n^2)}{(m-n^2)(n^2-m)}\)

= \(\displaystyle \L \frac{2n^2-2m + m-n^2}{(m-n^2)(n^2-m)}\)

= \(\displaystyle \L \frac{(n^2-m)}{(m-n^2)(n^2-m)}\)

...keep going. What can you now cancel? You will notice that your denominator will be (m-n^2)... you can switch that around so the largest term is first, and move that negative up to the numerator so it looks good.
 
Helen said:
2
______ +
m-n^2

1
______
n^2-m



Can you tell me if my answer is correct?

3
______
m-n^2

John is making the problem too complicated....

2/(m - n^2) + 1/(n^2 - m)

= 2/(m - n^2) - 1/(m - n^2)

= 1/(m - n^2)..............That's it
 
Re: Perform the indicated operation.

jwpaine said:
Or better yet...
(2 / (m - n^2)) + (1 / (n^2 - m))
However John, those 2 sets you added are not required "mathematically",
and in my opinion could cause confusion with a learning student.

My opinion...to quote TKHunny: others not welcome :D
 
Intermediate Algebra

Denis, Jwpaine, Subhotosh Khan, I thank you for your help. Helen
 
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