1) Đơn giản biểu thức SAU khi bỏ dấu ngoặc:
a) - a - (b - a - c) = -a - b + a + c = -b + c
b) - (a - c) - (a - b - c) = - a + c - a + b + c = - 2a + 2c + 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 = -2a
a) \(-a-\left(b-a-c\right)=-a+b+a+c=b+c\)
b) \(-\left(a-c\right)-\left(a-b-c\right)=-a+c-a+b+c=-2a+2c+b\)
c) \(b-\left(b+a-c\right)=b-b-a+c=-a+c\)
d) \(-\left(a-b-c\right)-\left(a+b+c\right)=-a+b+c-a-b-c=-2a\)
a) \(-a-b+a+c=c-b\)
b) \(-a+c-a+b-c=b-2a\)
c)\(b-b-a+c=c-a\)
d) \(-a+b-c-a-b-c=-2a-2c\)