Question

1,Rút gọn
A=(\(\dfrac{2x+1}{x\sqrt{x}+1}-\dfrac{\sqrt{x}}{x-\sqrt{x}+1}\))x(x-\(\dfrac{x-4}{\sqrt{x}-2}\))với x≥0;x≠4
2,Xác định a,b để đồ thị hàm số y=ax+b đi qua điểm A(2;1) vàB(1;2)

Answer 1

\(1,A=\dfrac{2x+1-x}{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}\cdot\left(x-\sqrt{x}-2\right)\\ A=\dfrac{\left(x+1\right)\left(\sqrt{x}+1\right)\left(\sqrt{x}-2\right)}{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}=\dfrac{\left(x+1\right)\left(\sqrt{x}-2\right)}{x-\sqrt{x}+1}\\ 2,\Leftrightarrow\left\{{}\begin{matrix}2a-b=1\\a-b=2\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}a=-1\\b=-3\end{matrix}\right.\Leftrightarrow y=-x-3\)