Thu gọn T=A-B

a)               Điều kiện :  x≥0 , x≠4 

T=A−B=xx−2−2x+2+4xx−4=xx+2−2.x−2−4xx−2x+2         

                        =x+2x−2x+4−4xx−2x+2 =x−4x+4x−2x+2=x−22x−2x+2=x−2x+2