Question 95578
((3x^a y^b)^3/ (-3x^a y^b)^2 )^2 

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[(27x^(3a)y^(3b)) / (9x^(2a)y^(2b)]^2

= [3x^(a)y^(b)]^2

= 9x^(2a)y^(2b)

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Cheers,
Stan H>