（0.5x^5y^2-4分之3x^4y^5-12分之1x^3y^2)/(-4分之1x^3y^2)
=0.5x^5y^2/(-4分之1x^3y^2)-4分之3x^4y^5/(-4分之1x^3y^2)-12分之1x^3y^2/(-4分之1x^3y^2)
=-2x^2+3xy^3+3分之1
[(2xy-3)(2xy+3)+(xy+3)^2]/xy
=(4x²y²-9+x²y²+6xy+9)/xy
=(5x²y²+6xy)/xy
=5xy+6