4x^2y-[2xy-3(xy-x)+4x^2y] 先化简,再求值,其中x=1/3,y=3/4

来源:学生作业帮助网 编辑:六六作业网 时间:2024/11/01 07:22:09
4x^2y-[2xy-3(xy-x)+4x^2y]先化简,再求值,其中x=1/3,y=3/44x^2y-[2xy-3(xy-x)+4x^2y]先化简,再求值,其中x=1/3,y=3/44x^2y-[2

4x^2y-[2xy-3(xy-x)+4x^2y] 先化简,再求值,其中x=1/3,y=3/4
4x^2y-[2xy-3(xy-x)+4x^2y] 先化简,再求值,其中x=1/3,y=3/4

4x^2y-[2xy-3(xy-x)+4x^2y] 先化简,再求值,其中x=1/3,y=3/4
化简得=4x^2y-[2xy-3xy+3x+4x^2y]
=4x^2y-2xy+3xy-3x-4x^2y
=xy-3x
当x=1/3,y=3/4时,xy-3x=1/4-1=-3/4