问题
填空题
已知xy=3,则x
|
答案
由xy=3,可知x、y同号,
①当x>0时,
x
=y x
=x2y x
=xy
,3
②当x<0时,
x
=-y x
=-x2y x
=-xy
.3
故填:±
.3
已知xy=3,则x
|
由xy=3,可知x、y同号,
①当x>0时,
x
=y x
=x2y x
=xy
,3
②当x<0时,
x
=-y x
=-x2y x
=-xy
.3
故填:±
.3