\(\begin{array}{l} P = \dfrac{{\left( {\sqrt x + 1} \right)\left( {\sqrt x + 2} \right) + 2\sqrt x \left( {\sqrt x – 2} \right) – 2 – 5\sqrt x }}{{\left( {\sqrt x + 2} \right)\left( {\sqrt x – 2} \right)}}\\ = \dfrac{{x + 3\sqrt x + 2 + 2x – 4\sqrt x – 2 – 5\sqrt x }}{{\left( {\sqrt x + 2} \right)\left( {\sqrt x – 2} \right)}}\\ = \dfrac{{3x – 6\sqrt x }}{{\left( {\sqrt x + 2} \right)\left( {\sqrt x – 2} \right)}}\\ = \dfrac{{3\sqrt x \left( {\sqrt x – 2} \right)}}{{\left( {\sqrt x + 2} \right)\left( {\sqrt x – 2} \right)}}\\ = \dfrac{{3\sqrt x }}{{\sqrt x + 2}} \end{array}\)
Đáp án:
Giải thích các bước giải:
Đáp án:
\(\dfrac{{3\sqrt x }}{{\sqrt x + 2}}\)
Giải thích các bước giải:
\(\begin{array}{l}
P = \dfrac{{\left( {\sqrt x + 1} \right)\left( {\sqrt x + 2} \right) + 2\sqrt x \left( {\sqrt x – 2} \right) – 2 – 5\sqrt x }}{{\left( {\sqrt x + 2} \right)\left( {\sqrt x – 2} \right)}}\\
= \dfrac{{x + 3\sqrt x + 2 + 2x – 4\sqrt x – 2 – 5\sqrt x }}{{\left( {\sqrt x + 2} \right)\left( {\sqrt x – 2} \right)}}\\
= \dfrac{{3x – 6\sqrt x }}{{\left( {\sqrt x + 2} \right)\left( {\sqrt x – 2} \right)}}\\
= \dfrac{{3\sqrt x \left( {\sqrt x – 2} \right)}}{{\left( {\sqrt x + 2} \right)\left( {\sqrt x – 2} \right)}}\\
= \dfrac{{3\sqrt x }}{{\sqrt x + 2}}
\end{array}\)