Question 209709
4x^2{x^(-2)y^(-4)}^(-1),,,,,,remember (x^a)^b = x^(ab)
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4x^2 { x^2y^4},,,,but  x^2*x^2 = x^(2+2)=x^4
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4x^4y^4
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check,,,let  x=2,,y=3,,,,both  original  and  answer  = 5184,,,,ok