( )( )− + = − ++ − = + −B. 67 8 19 67 8 19A. 52 19 9 52 19 9=...

Câu 11.

( )

− + = − ++ − = + −b. 67 8 19 67 8 19a. 52 19 9 52 19 9= −= + 33 9 75 19 = 42 56