(二分之一xy^2)^3・（-4x^2y)^2

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(xy^2/陆塌斗衫宴2)^3*(-4x^2y)^2
=x^3y^6/早磨8 * 16x^4y^2
=16/8x^(4+3)y^(6+2)
=2x^7y^8

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[(1/2)xy^2)^3]・（-4x^2y)^2
=[(1/8)x^3y^6]・（16x^4y^2)
=2x^7y^8

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