来自来疆亮的问题
【(x+y+z)+(x-y-z)-(x-y+z)先去括号,再合并同类项急死了.】
(x+y+z)+(x-y-z)-(x-y+z)先去括号,再合并同类项
急死了.
1回答
2020-07-17 18:01
【(x+y+z)+(x-y-z)-(x-y+z)先去括号,再合并同类项急死了.】
(x+y+z)+(x-y-z)-(x-y+z)先去括号,再合并同类项
急死了.
(x+y+z)+(x-y-z)-(x-y+z)
=x+y+z+x-y-z-x+y-z
=x+y-z