Question 126200
[(a/b)+(a+b)/(a-b)]/[(a/b)-(a-b)/(a+b)] 

= {[a(a-b)+b(a+b)]/[b(a-b)]} / {[a(a+b)-b(a-b)]/[b(a+b)]

= {[a^2+b^2]/b(a-b)]} / {[a^2-b^2]/[b(a+b)]}

Invert the denominator and multiply after cancelling where you can:

= (a^2+b^2)

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Cheers,
Stan H.