Bài 6: 1/ Đơn giản biểu thức sau khi bỏ ngoặc:
a/ -a – (b – a – c)
b/ – (a – c) – (a – b + c)
c/ b – ( b+a – c)
d/ – (a – b + c) – (a + b + c)
Bài 6: 1/ Đơn giản biểu thức sau khi bỏ ngoặc:
a/ -a – (b – a – c)
b/ – (a – c) – (a – b + c)
c/ b – ( b+a – c)
d/ – (a – b + c) – (a + b + c)
a) `-a-(b-a-c)`
`=-a-b+a+c`
`=(-a+a)-b+c`
`=-b+c`
b) `-(a-c)-(a-b+c)`
`=-a+c-a+b-c`
`=(-a-a)+(c-c)+b`
`=-2a+b`
c) `b-(b+a-c)`
`=b-b-a+c`
`=-a+c`
d) `-(a-b+c)-(a+b+c)`
`=-a+b-c-a-b-c`
`=(-a-a)+(b-b)+(-c-c)`
`=-2a-2c`
a/ `-a – (b – a – c)` `=-a-b+a+c` `=-b+c` `=c-b`
b/ `- (a – c) – (a – b + c)` `=−a+c−a+b−c` `=−2a+b`
c/ `b – ( b+a – c)` `=b−b−a+c` `=−a+c` `=c-a`
d/ `- (a – b + c) – (a + b + c)` `=−a+b−c−a−b−c` `=−2a−2c`