2xy-1/2（4xy-8x²y²）+2（3xy-5x²y²）,其中x=3/2,y=-2/3

题目

2xy-1/2（4xy-8x²y²）+2（3xy-5x²y²）,其中x=3/2,y=-2/3

答案

x=3/2,y=-2/3xy=3/2*(-2/3)=-12xy-1/2（4xy-8x²y²）+2（3xy-5x²y²）=2xy-2xy+4x²y²+6xy-10x²y²=(2-2+6)xy+(4-10)x²y²=6xy-6x²y²=6xy(1-xy)=-1*[1-(-1)...