a) (a - m) - (m - b + c) + (- b - c)
=a-m-m+b-c-b-c
=a-2x-2m
b) (a +b - c) - (- c + b ) + a
=a+b-c+c-b+a
=2a
c) (- a + b - c) - (- a - b - c)
=-a+b-c+a+b+c
=2b
d) (b + d) + ( - b - c) - ( c - a) - a
=b+d-b-c-c+a-a
=-d-2c
Thu gọn:
a) (a - m) - (m - b + c) + (- b - c)
= a - m - m + b - c - b - c
= a + ( - m - m ) + ( b - b ) + ( - c - c )
= a + ( - 2m ) + 0 + ( - 2m )
= a + [ ( - 2m ) + ( - 2m ) ]
= a + - 4m
b) (a + b - c) - (- c + b ) + a
= a + b - c + c - b + a
= ( a + a ) + ( - c + c ) + ( - b + b )
= 2a + 0 + 0
= 2a
c) (- a + b - c) - (- a - b - c)
= - a + b - c + a + b + c
= ( - a + a ) + ( b + b ) + ( c - c )
= 0 + 2b + 0
= 2b
d) (b + d) + ( - b - c) - ( c - a) - a
= b + d - b + c - c + a - a
= ( b - b ) + ( c - c ) + ( a - a ) + d
= 0 + 0 + 0 + d
= d
a)\(\left(a-m\right)-\left(m-b+c\right)+\left(-b-c\right)=a-m-m+b-c-b-c=a-2c-2m\)
b) \(\left(a+b-c\right)-\left(-c+b\right)+a=a+b-c+c-b+a=2a\)
c)\(\left(-a+b-c\right)-\left(-a-b-c\right)=-a+b-c+a+b+c=2b\)
d)\(\left(b+d\right)+\left(-b-c\right)-\left(c-a\right)-a=b+d-b-c-c+a=a-2c+d\)
a) (a-m) - (m-b+c) + (-b-c)
= a - m - m + b - c - b - c
= a - 2m - 2c
b) ( a+b-c ) - ( -c+b ) + a
= a + b - c + c - b + a
= 2a
c) ( -a+b-c ) - (-a-b-c)
= -a + b -c + a + b + c
= 2b
d) (b+d) + (-b-c) - (c-a) -a
= b + d -b -c -c + a -a
= d - 2c
