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化简(X方-2X分之X+2.

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/05/29 04:13:02
化简(X方-2X分之X+2.
化简(X方-2X分之X+2-X方-4X+4分之X-1)除以X分之X-4,其中,
X=负2分之5
[(x+2)/(x^2-2x)-(x-1)/(x^2-4x+4)]/[(x-4)/x]
=[(x+2)/x(x-2)-(x-1)/(x-2)^2]*[x/(x-4)]
={[(x+2)(x-2)-x(x-1)]/x(x-2)^2}*[x/(x-4)]
=[(x^2-4-x^2+x)/x(x-2)^2*[x/(x-4)]
=(x-4)*x/[x(x-2)^2(x-4)]
=1/(x-2)^2
=1/(-5/2-2)^2
=1/(81/4)
=4/81