Cho biểu thức: A = (2 căn bậc hai x - 9) / (x - 5 căn bậc hai x + 6) - (căn bậc hai x + 3)
Giải thích
DKXD: x ≥ 0, x ≠ 4, x ≠ 9
P=2x−9x−5x+6−x+3x−2+2x+1x−3
=2x−9−x+3x−3+2x+1x−2x−2x−3
=2x−9−x+9+2x−3x−2x−2x−3
=x−x−2x−2x−3
=x+1x−2x−2x−3=x+1x−3
DKXD: x ≥ 0, x ≠ 4, x ≠ 9
P=2x−9x−5x+6−x+3x−2+2x+1x−3
=2x−9−x+3x−3+2x+1x−2x−2x−3
=2x−9−x+9+2x−3x−2x−2x−3
=x−x−2x−2x−3
=x+1x−2x−2x−3=x+1x−3