已知X=-√2,y=-3,z=1,求3x^2y-[ 2x^2y-(2xyz-x^2z)+4x^2z ].

问题描述:

已知X=-√2,y=-3,z=1,求3x^2y-[ 2x^2y-(2xyz-x^2z)+4x^2z ].

3x^2y-[ 2x^2y-(2xyz-x^2z)+4x^2z ]
=3x^2y-2x^2y+2xyz-x^2z+4x^2z
=x^2y+3x^2z+2xyz
=x^2(y+3z)+2xyz
=x^2(-3+3)+2(-√2)(-3)*1
=6√2