Question

ac giúp e giải bài này chi tiết với ạ. e cảm ơn ac ạ

Answer 1

a: \(A=\dfrac{15\sqrt{x}-\left(3x+9\sqrt{x}-2\sqrt{x}-6\right)-\left(2x-2\sqrt{x}+3\sqrt{x}-3\right)}{\left(\sqrt{x}+3\right)\left(\sqrt{x}-1\right)}\)

\(=\dfrac{15\sqrt{x}-3x-7\sqrt{x}+6-2x-\sqrt{x}+3}{\left(\sqrt{x}+3\right)\left(\sqrt{x}-1\right)}\)

\(=\dfrac{-5x+7\sqrt{x}+9}{\left(\sqrt{x}+3\right)\left(\sqrt{x}-1\right)}\)

b: Để A=1/2 thì \(2\left(-5x+7\sqrt{x}+9\right)=x+2\sqrt{x}-3\)

\(\Leftrightarrow-10x+14\sqrt{x}+18-x-2\sqrt{x}+3=0\)

\(\Leftrightarrow-11x+12\sqrt{x}+21=0\)

hay \(x=\left(\dfrac{6+\sqrt{267}}{2}\right)^2\)