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代入求值若|(x-2)^2+y+1|=0,化简求值2(x-1/2y)×(2x+y)-(2x-y)^2+y(x+2y)

题目详情
代入求值若|(x-2)^2+y+1|=0,化简求值2(x-1/2y)×(2x+y)-(2x-y)^2+y(x+2y)
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答案和解析
(2X Y)^2-(2X-Y)(X Y)-2(X-2Y)(X 2Y)解原式=4X^2 Y^2 4XY-2X^2-2XY XY Y^2-2(X^2-4Y^2)=4X^2 Y^2 4XY-2X^2-2XY XY Y^2-2X^2 8Y^2=4X^2-2X^2-2X^2 Y^2 Y^2 8Y^2 4XY-2XY XY=10Y^2 3XY把x= ,y=-2代入就行了....