若x-y=4,则18-x+y=?
问题描述:
若x-y=4,则18-x+y=?
答
18-x+y
=18-(x-y)
=18-4
=14
若x-y=4,则18-x+y=?
18-x+y
=18-(x-y)
=18-4
=14