Giải thích các bước giải:
Bài 1:
a) $\sqrt{8}-2\sqrt 5+3\sqrt 8$
$=4\sqrt 8-2\sqrt 5$
b) $\sqrt{130}+\sqrt{96}+95\sqrt{\dfrac{2}{3}}-\sqrt 6$
$=\sqrt{130}+4\sqrt 6+\dfrac{95\sqrt 6}{3}-\sqrt 6$
$=\sqrt{130}+\dfrac{104}{3}\sqrt 6$
c) $\sqrt{150}+\sqrt{96}+95\sqrt{\dfrac{2}{3}}-\sqrt 6$
$=5\sqrt 6+4\sqrt 6+\dfrac{95\sqrt 6}{3}-\sqrt 6$
$=\dfrac{119}{3}\sqrt 6$.
Bài 2:
ĐKXĐ: $x\ge 0$
$\sqrt{9x}-3\sqrt{x}=6-4\sqrt x$
$⇔3\sqrt x-3\sqrt x=6-4\sqrt x$
$⇔4\sqrt x=6$
$⇔16x=36$
$⇔x=\dfrac{9}{4}$
Vậy $S=\left\{\dfrac{9}{4}\right\}$.
