化简求值：－8x2－5x(－x+3y)+(3x+2y)(x－y),其中x=2,y=－1.

－8x2－5x(－x+3y)+(3x+2y)(x－y),其中x=2,y=－1.
=-8x²+5x²-15xy+3x²-xy-2y²
=-16xy-2y²
=-16*(2)*(-1)-2*(-1)²
=32-2
=30