Question

Phá ngoặc rồi viết gọn 

1 , a - ( a - b - c ) - ( b - c -a ) - ( c - b -a )

2 , - ( a + b + c ) - ( b - c -a ) + ( 1 - a - b ) - ( c - 3b )

3 , ( b - c - 6 ) - ( 7 - a + b ) + c

4 , - ( 3b - 2a - c ) - ( a - b - c ) - ( a - 2b -+ 2c )

5 , ( 4a - 3b + 2c ) - ( 4b - 3c - 2a ) - ( 4c - 3a + 2b ) + ( a - b ) - c

6, 2a - { a - b [ a - b - ( a + b + c ) + 2b ] - c - b }

 

Answer 1

a - ( a - b - c ) - ( b - c - a ) - ( c - b - a)

= a - a + b + c - b + c + a - c + b + a

= ( a -a + a ) + ( b - b + b ) + ( c + c - c)              ( vì mình ko có ngoặc vuông nên chỉ thế này thôi)

= a + b + c

Bạn tự làm hết nha

Answer 2

1)=>a-a+b+b-b+c+a-c+b+a=2a+2b+c=2(a+b)+c

2)=>-a-b-c-b+c+a+1-a-b-c+3b=-a

3)=>b-c-6-7+a-b+c=-13+a

4)-3b+2a+c-a+b+c-a+2b-2c=0

5)=>4a-3b+2c-4b+3c+2a-4c+3a-2b+a-b-c=-2a-10b-2c

Answer 3

 2a - { a - b [ a - b - ( a + b + c ) + 2b ] - c - b }

=2a-{a-b[a-b-a-b-c+2b]-c-b}

=2a-{a-bc-c-b}

=2a-a-bc-c-b

=a-bc-b-c