Question

Rút gọn biểu thức :

 \(A=\left(a+b-c\right)+\left(a-b\right)-\left(a-b\right)-\left(a-b-c\right)\)

Answer 1

Ta có: \(A=\left(a+b-c\right)+\left(a-b\right)-\left(a-b\right)-\left(a-b-c\right).\)

\(\Rightarrow A=a+b-c+a+b+a+b+a+b+c\)

\(\Rightarrow A=a+b+a+b+a+b+a+b\)

\(\Rightarrow A=3.\left(a+b\right)\)

Answer 2

Rút gọn biểu thức :

 A=(a+b−c)+(a−b)−(a−b)−(a−b−c)

Ta có: A=(a+b−c)+(a−b)−(a−b)−(a−b−c).

⇒A=a+b−c+a+b+a+b+a+b+c

⇒A=a+b+a+b+a+b+a+b

⇒A=3.(a+b)

 nhé !

Answer 3

\(A=a+b-c+a-b-a+b-a+b+c\)

\(=2b.\)