这道题目要先化简,然后在求值就很简单了!
x2y-(2xy2+x2y)+(2xy2+4x3y)
=X^2y-2X*y^2-x^2y+2xy^2+4x^3y
=-X^2y-X^2y-2xy^2+2xy^2+4X^3y
=4X^3y
把X=-2,y=1代入后得到4*-8*1=-32
不懂的欢迎追问,
这道题目要先化简,然后在求值就很简单了!
x2y-(2xy2+x2y)+(2xy2+4x3y)
=X^2y-2X*y^2-x^2y+2xy^2+4x^3y
=-X^2y-X^2y-2xy^2+2xy^2+4X^3y
=4X^3y
把X=-2,y=1代入后得到4*-8*1=-32
不懂的欢迎追问,