`-5x+7√x+12=0`
`⇔-5x+12√x-5√x+12=0`
`⇔-√x(5√x-12)-(5√x-12)=0`
`⇔(5√x-12)(-√x-1)=0`
`⇔`\(\left[ \begin{array}{l}5√x-12=0\\-√x-1=0\end{array} \right.\)
`⇔`\(\left[ \begin{array}{l}√x=7\\√x=-1 (Vô lý)\end{array} \right.\)
`⇔x=49`
`√x²-6x+9 =√4+2√3`
`⇔√(x-3)²=√(√3+1)²`
`⇔`I`x``-``3`I`=√3+1`
`⇔x-3=√3+1` hoặc `x-3=-√3-1`
`⇔x=4+√3` hoặc `x=2-√3`