Cho biểu thức: P=(x^2-3x/x^2-9-1):(9-x^2/x^2+x-6-x-3/2-x-x-2/x+3) .Rút gọn P
Giải thích
P=x2−3xx2−9−1:9−x2x2+x−6−x−32−x−x−2x+3DK:x≠±3;x≠2
=xx−3x+3x−3−1:9−x2x−2x+3+x−3x−2−x−2x+3
=xx+3−1:9−x2x−2x+3+x−3x+3x−2x+3−x−22x−2x+3
=x−x−3x+3:9−x2+x2−9−x2+4x−4x−2x+3
=−3x+3:−x2+4x−4x−2x+3
=−3x+3.x−2x+3−x−22
=3x−2