设|X-2|+(Y+1/4)^2=0,试求代数式X^2(X^2-XY+Y)-X(X^3-2X^2Y+XY-1)的值._数学解答

设|X-2|+(Y+1/4)^2=0,试求代数式X^2(X^2-XY+Y)-X(X^3-2X^2Y+XY-1)的值.

人气：163 ℃　时间：2020-01-28 10:00:50

解答

由|X-2|+(Y+1/4)^2=0可得X-2=0,Y+1/4=0,即X=2,Y=-1/4
原式=X(X^3-X^2Y+XY-X^3+2X^2Y-XY+1
=X(X^2Y+1)
将X=2.Y=-1/4带入得,原式=2 x (4 x( -1/4 )+1)=0