Đáp án:
Giải thích các bước giải:
Cậu viết sai điều kiện rồi nhé ^^
ĐKXĐ : \(\left\{ \begin{array}{l}\sqrt{x}+3\ne0\\\sqrt{x}-3\ne0\\x-9\ne0\end{array} \right.\) `=>` \(\left\{\begin{array}{l}\sqrt{x}\ne-3\\\sqrt{x}\ne3\\x-9\ne0\\x\ge0\end{array} \right.\) `=>` \(\left\{\begin{array}{l}x\in\emptyset\\x\ne9\\x\ne9\\x\ge0\end{array} \right.\) `=>` \(\left\{ \begin{array}{l}x\ge0\\x\ne9\end{array} \right.\)
`A = ((2sqrtx)/(sqrtx+3)+(sqrtx)/(sqrtx-3)-(3x+3)/(x+9)) \div ((2sqrtx-2)/(sqrtx-3)-1)`
`= ((2sqrtx)/(sqrtx+3)+(sqrtx)/(sqrtx-3)-(3x+3)/((sqrtx-3)(sqrtx+3)))\div(2sqrtx-2-(sqrtx-3))/(sqrtx-3)`
`= (2sqrtx(sqrtx-3)+(sqrtx+3)sqrtx-(3x+3))/((sqrtx-3)(sqrtx+3)) \div (2sqrtx-2-sqrtx+3)/(sqrtx-3)`
`= (2x-6sqrtx+x+3sqrtx-3x-3)/((sqrtx-3)(sqrtx+3)) \div (sqrtx-3)/(sqrtx+1)`
`= (-3sqrtx-3)/((sqrtx-3)(sqrtx+3)) * (sqrtx-3)/(sqrtx+1)`
`= (-3(sqrtx+1))/(sqrtx+3) * 1/(sqrtx+1)`
`= (-3)/(sqrtx+3)`
