化简求值[x（x²y²-xy）-y（x²-x²y²）]÷3x²y x=1 y=3特急

化简求值[x（x²y²-xy）-y（x²-x²y²）]÷3x²y x=1 y=3特急
化简求值[x（x²y²-xy）-y（x²-x²y²）]÷3x²y x=1 y=3
特急

化简求值[x（x²y²-xy）-y（x²-x²y²）]÷3x²y x=1 y=3特急
原式=(x3y2-x2y-x2y+x2y3)/3x2y
= x3y2/3x2y-2x2y/3x2y+x2y3/3x2y
=xy/3=2/3+y2/3
把x=1,y=3代入
=1×3/3-2/3+3^2/3=10/3