问题
计算题
先化简,再求值:[(x﹣y)2+(x+y)(x﹣y)]÷2x,其中x=2005,y=2004.
答案
解:[(x﹣y)2+(x+y)(x﹣y)]÷2x,
=(x2﹣2xy+y2+x2﹣y2)÷2x,
=(2x2﹣2xy)÷2x,
=x﹣y,
当x=2005,y=2004时,
原式=2005﹣2004=1.
先化简,再求值:[(x﹣y)2+(x+y)(x﹣y)]÷2x,其中x=2005,y=2004.
解:[(x﹣y)2+(x+y)(x﹣y)]÷2x,
=(x2﹣2xy+y2+x2﹣y2)÷2x,
=(2x2﹣2xy)÷2x,
=x﹣y,
当x=2005,y=2004时,
原式=2005﹣2004=1.