若2X-Y=3,则4X-2X-Y=?
问题描述:
若2X-Y=3,则4X-2X-Y=?
答
4X-2X-Y
=2X-Y
=3
答
4X-2X-Y=2X-Y=3
答
方法1:4X-2X-Y
=2X-Y
=3
方法2:2X-Y=3则Y=2X-3代入4X-2X-Y=4X-2X-(2X-3)=3
答
4X-2X-Y=
=2x-y
=3