2 câu trả lời
Đáp án + Giải thích các bước giải:
`a+\sqrt{a} -6`
`= a+3\sqrt{a}-2\sqrt{a}-6`
`= \sqrt{a^2} +3\sqrt{a}-2\sqrt{a}-6`
`= \sqrt{a}(\sqrt{a}+3)-2(\sqrt{a}+3)`
`= (\sqrt{a}+3)(\sqrt{a}-2)`
________________
`x+5\sqrt{x}+6`
`= x+2\sqrt{x}+3\sqrt{x}+6`
`= \sqrt{x^2}+2\sqrt{x}+3\sqrt{x}+6`
`= \sqrt{x}(\sqrt{x}+2)+3(\sqrt{x}+2)`
`= (\sqrt{x}+2)(\sqrt{x}+3)`
$a)$ $a$ $+$ $\sqrt{a}$ $-$ $6$
$=$ $a$ $-$ $2$ $\sqrt{a}$ $+$ $3$ $\sqrt{a}$ $-$ $6$
$=$ $\sqrt{a}$ ($\sqrt{a}$ $-$ $2$) $+$ $3$ ($\sqrt{a}$ $-$ $2$)
$=$ ($\sqrt{a}$ $-$ $2$) ($\sqrt{a}$ $+$ $3$)
..........................................................................................................
$b)$ $x$ $+$ $5$$\sqrt{x}$ $+$ $6$
$=$ $x$ $+$ $2$$\sqrt{x}$ $+$ $3$$\sqrt{x}$ $+$ $6$
$=$ $\sqrt{x^2}$ $+$ $2$$\sqrt{x}$ $+$ $3$$\sqrt{x}$ $+$ $6$
$=$ $\sqrt{x}$ ($\sqrt{x}$ $+$ $2$) $+$ $3$ ($\sqrt{x}$ $+$ $2$)
$=$ ($\sqrt{x}$ $+$ $2$) ($\sqrt{x}$ $+$ $3$)
$\text{HCR}$