Question

Thu gọn tổng sau : 

a) ( a - b + c -d ) - ( a+ b + c + d )

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

c) - ( a - b - c ) + ( b - c + d ) - ( -a + b + d )

Answer 1

a) ( a - b + c -d ) - ( a+ b + c + d ) = a - b + c - d - a - b - c - d = -2b - 2d 

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

c) - ( a - b - c ) + ( b - c + d ) - ( -a + b + d )

Answer 2

a) (a-b+c-d)-(a+b+c+d)

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

=-2b-2d

=2(b-d)

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

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

=-a+b-2c

c) -(a-b-c)+(b-c+d)-(-a+b+d)

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

=b

Answer 3

a) = -2b-2d

b) = -a+b-2c

c) = b