Question

Bài 1 : Chứng tỏ :

(a + b ) - (b - a)  + c  = 2a + c

Answer 1

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

Answer 2

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

=> a + b - b + a + c = 2a + c

=> a + 0 + a + c = 2a + c

=> 2a + c = 2a + c

Answer 3

( a + b ) - ( b - a ) = a + b - b + a + c = ( a + a ) + ( b - b ) + c = 2a + 0 + c = 2a + c

Answer 4

ta co (a+b)-(b-a)+c

=a+b-b+a+c

=2a+c 

tk mk nha ban