来自付明玉的问题
(a+b-c)-(b-a-c)去括号后等于多少,
(a+b-c)-(b-a-c)去括号后等于多少,
3回答
2019-12-31 18:53
(a+b-c)-(b-a-c)去括号后等于多少,
(a+b-c)-(b-a-c)去括号后等于多少,
(a+b-c)-(b-a-c)
=a+b-c-b+a+c
=2a
为什么前面括号式子去括号后符号不变?
因为-(b-a-c)可以看成是-1×(b-a-c)=-b+a+c