(3x-y)²-(2x+y)²-5x(x-y),其中x=4^2007,y=(-0.25)^2008,化简求值(3x-y)²-(2x+y)²-5x(x-y)=9x²-6xy+y²-(4x²+4xy+y²)-5x²+5xy=-5xy=-5×(4^2007)×(-1/4)^2008=-5×(4^2...