<PRE><B>Question 78602</B>
(x+1)/(x+3)(x-3) + 4(x-3) / (x+3)(x-3) + (x-1)(x-3) / (3-x)(x+3) 
Adjust the 3rd term so it has the same denominator as the 1st and 2nd terms.
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=(x+1)/(x+3)(x-3) + 4(x-3) / (x+3)(x-3) - (x-1)(x-3) / (x-3)(x+3) 
Combine the numerators over a single denominator, as follows:

=[x+1+4x-12-x^2+4x-3]/[(x-3)(x+3)]

=[-(x^2-9x+2]/[(x-3)(x+3)]

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Also,

 6 /(x-y) + 4x/(y^2 - x^2)
=6 /(x-y) - 4x/(x^2 - y^2)  
The least common denominator is (x-y)(x+y)
=6(x+y)/lcm - 4x/lcm
=[6x+6y-4x]/lcm
=[2x+6y]/[(x-y)(x+y)]
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Cheers,
Stan H.
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