Question

化简求值:(-1/3XY)²[xy(2x-y)-2x(xy-y²)],其中X=-3/2,Y=-2

Answer 1

先化简在求值
(-1/3XY)²×[xy(2x-y)-2x(xy-y)²],
=1/9x²y²*(2x²y-xy²-2x²y+2xy²)
=1/9x²y²*xy²
=1/9x³y^4
=1/9x(-3/2)³x(-2)^4
=-1/9x27/8x16
=-6

追问

1/9x(-3/2)³x(-2)^4
=-1/9x27/8x16 ??
1/9=-1/9???

追答

(-3/2)³=-27/8 呀，把负号放前面

Answer 2

简求值:(-1/3XY)²[xy(2x-y)-2x(xy-y²)]
=1/9*x^2y^2[2x^2y-xy^2-2x^2y+2xy^2]
=1/9*x^2y^2*xy^2
=1/9x^3y^4
X=-3/2,Y=-2
=1/9*(-27/8)*(16)
=-6