Question

Cho A=\(\dfrac{1}{x^2-\sqrt{x}}.\dfrac{\sqrt{x}+1}{x\sqrt{x}+x+\sqrt{x}}\)

a)Tìm điều kiện để A có nghĩa

b)Rút gọn A

Answer 1

a) A có nghĩa khi \(x>0;x\ne1\)

b)

\(A=\dfrac{1}{x^2-\sqrt{x}}:\dfrac{\sqrt{x}+1}{x\sqrt{x}+x+\sqrt{x}}\\ A=\dfrac{1}{\sqrt{x}\left(\sqrt{x}^3-1\right)}:\dfrac{\sqrt{x}+1}{\sqrt{x}\left(x+\sqrt{x}+1\right)}\\ A=\dfrac{1}{\sqrt{x}\left(\sqrt{x}-1\right)\left(x+\sqrt{x}+1\right)}:\dfrac{\sqrt{x}+1}{\sqrt{x}\left(x+\sqrt{x}+1\right)}\\ A=\dfrac{\sqrt{x}\left(x+\sqrt{x}+1\right)}{\sqrt{x}\left(\sqrt{x}-1\right)\left(x+\sqrt{x}+1\right)\left(\sqrt{x}+1\right)}\\ A=\dfrac{1}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}=\dfrac{1}{x-1}\)

Answer 2

Xin lỗi nha...Chỗ giữa kia thì dấu''.''thay bằng dấu'':'' hộ mình với.