How do you do this math problem:
x/x^2-y^2 + y/x^2-y^2
answer options:
A. 1/x-y
B. 1/x+y
C. -1/x+y
D. 1/y-x

Question

How do you do this math problem: 
x/x^2-y^2 + y/x^2-y^2
answer options: 
A. 1/x-y
B. 1/x+y
C. -1/x+y
D. 1/y-x

zyberg · Answer

Do you know $$\frac{ a }{ b } + \frac{ d }{ c } = \frac{ ac + db}{ bc }$$?

srtauser · Answer

no
Thank you again!
 So it's B??

welshfella · Answer

No

can you factor  x^2 - y^2 ?

welshfella · Answer

the result of the addition is 

   x + y
---------
 x^2 - y^2

If we factor the denominator we can simplify

srtauser · Answer

ok Its C

srtauser · Answer

I though when you simplify x^2-y^2 you get (x+y)(x-y)

welshfella · Answer

I think you are guessing

x^2 - y^2  is  an example of the difference of 2 squares 

x^2 - y^2 =  ( x + y)( x - y)

welshfella · Answer

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