化简求值【(x-2y)2-x(x-4y) -8xy】÷4y,其中x=-1.5,y=2

问题描述:

化简求值【(x-2y)2-x(x-4y) -8xy】÷4y,其中x=-1.5,y=2

【(x-2y)2-x(x-4y) -8xy】÷4y
=【(x-2y)2-x(x-2y-2y) -8xy】÷4y
=【(x-2y)2-x(x-2y)+2xy -8xy】÷4y
=【X2+(x-2y)2-2x(x-2y)+x(x-2y)-x2+2xy -8xy】÷4y
=【(x-2y-x)2-x2+x(x-2y)+2xy-8xy】÷4y
=【(-2y)2-x2+x2-2xy+2xy-8xy】÷4y
=【4y2-x2+x2-2xy+2xy-8xy】÷4y
=【4y2-8xy】÷4y
=y-2x=2-2*(-1.5)
=2+3=5