化简求值4x²y-[6xy-2(4xy-2)-x²y]+1,其中x=负二分之一,y=4 过程_数学解答

化简求值4x²y-[6xy-2(4xy-2)-x²y]+1,其中x=负二分之一,y=4 过程

人气：365 ℃　时间：2020-06-04 12:30:17

解答

4x²y-[6xy-2(4xy-2)-x²y]+1
=4x^2y-6xy+8xy-4+x^2y+1
=5x^2y+2xy-3
=5(-1/2)^2*4+2(-1/2)*4-3
=5-4-3
=-2