已知x+2y-3x=-1/3,xyz=2,求3/2x²yz+3xy²z-9/2xyz的值 help~
问题描述:
已知x+2y-3x=-1/3,xyz=2,求3/2x²yz+3xy²z-9/2xyz的值 help~
答
x+2y-3x=-1/3,即2y-2x=-1/3,y=x-1/6
3/2x²yz+3xy²z-9/2xyz
=xyz(3x/2+3y-9/2)
=2(3x/2+3(x-1/6)-9/2)
=2(3x/2+3x-1/2-9/2)
=2(3x/2+3x-10/2)
=3x+6x-10
=9x-10
答
3/2x²yz+3xy²z-9/2xyz
=3/2xyz(x+2y-3z)
=3/2*2*(-1/3)
=-1