Đơn giản biểu thức sau khi bỏ dấu ngoặc:
a) -a -( b - a - c )
b) - ( a - c ) -( a - b + c )
c) b - ( b + a - c )
d) - ( a - b + c ) - ( a + b+ c)
e) ( a + b ) - ( a -b ) + ( a -c ) - ( a + c )
g) ( a + b - c ) + ( a - b + c ) - ( b + c - a ) - ( a - b -c )
I don't know
a)-a-b+a+c
b)-a+c-a+b-c
c)b-b-a+c
d)-a+b-c-a-b-c
e)a+b-a+b+a-c-a-c
g)a+b-c+a-b+c-b-c+a-a+b+c