Question 108382
((x^2+2)/(x^2+2x-15)) + ((7-4x)/(15-2x-x^2))
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The denominators are the same except for their sign.
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= ((x^2+2)/(x^2+2x-15)) + ((4x-7)/(x^2+2x-15))

= [x^2+4x-5]/[x^2+2x-15]

= [(x+5)(x-1)] / [(x+5)(x-3)]

Concel the (x+5) which is common to numerator and denominator.

= (x-1)/(x-3)

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Cheers,
Stan H.