若X+Y=2,则约分|X^2-Y^2|/X-Y的结果.
问题描述:
若X+Y=2,则约分|X^2-Y^2|/X-Y的结果.
答
X+Y=2
|X^2-Y^2|/(X-Y)
=|(X+Y)(X-Y)|/(X-Y)
=|2(X-Y)|/(X-Y)
=±2(X-Y)/(X-Y)
=±2