a. – ( a – b + c ) – ( c – a ) = – a + b – c – c + a =b – 2c b. a – ( – b + a – c ) = a + b – a + c = b + c Bình luận
a. – ( a – b + c ) – ( c – a )
= – a + b – c – c + a
=b – 2c
b. a – ( – b + a – c )
= a + b – a + c
= b + c
a) -(a-b+c)-(c-a)
=-a+b-c-c+a
=b-2c
b)a-(-b+a-c)
=a+b-a+c
=b+c