Đáp án:
\({P = \frac{{x\sqrt x {\rm{ \;}} - 3x + 6\sqrt x {\rm{ \;}} - 30}}{{\left( {\sqrt x {\rm{ \;}} - 3} \right)\left( {\sqrt x {\rm{ \;}} + 1} \right)}}}\)
Giải thích các bước giải:
\(\begin{array}{*{20}{l}}
{DK:x \ge 0;x \ne 9}\\
{P = \frac{{x\sqrt x {\rm{ \;}} - 3}}{{\left( {\sqrt x {\rm{ \;}} - 3} \right)\left( {\sqrt x {\rm{ \;}} + 1} \right)}} - \frac{{2\sqrt x {\rm{ \;}} - 6}}{{\sqrt x {\rm{ \;}} + 1}} - \frac{{\sqrt x {\rm{ \;}} + 3}}{{\sqrt x {\rm{ \;}} - 3}}}\\
{{\rm{\;}} = \frac{{x\sqrt x {\rm{ \;}} - 3 - 2x + 6\sqrt x {\rm{ \;}} + 6\sqrt x {\rm{ \;}} - 18 - x - 6\sqrt x {\rm{ \;}} - 9}}{{\left( {\sqrt x {\rm{ \;}} - 3} \right)\left( {\sqrt x {\rm{ \;}} + 1} \right)}}}\\
{ = \frac{{x\sqrt x {\rm{ \;}} - 3x + 6\sqrt x {\rm{ \;}} - 30}}{{\left( {\sqrt x {\rm{ \;}} - 3} \right)\left( {\sqrt x {\rm{ \;}} + 1} \right)}}}\\
{}\\
{}\\
{}\\
{}
\end{array}\)
