Giải thích các bước giải:
b) `x^2-2sqrt5x+5=0`
`=>(x-sqrt5)^2=0`
`=>x-sqrt5=0`
`=>x=sqrt5`
c) `4x^2-4sqrt3x+3=0`
`=>(2x-sqrt3)^2=0`
`=>2x-sqrt3=0`
`=>2x=sqrt3=>x=sqrt3/2`
d) `sqrt(x^2+6x+9)=5`
`=>sqrt((x+3)^2)=5`
`=>|x+3|=5`
`=>`\(\left[ \begin{array}{l}x+3=5\\x+3=-5\end{array} \right.\) `=>`\(\left[ \begin{array}{l}x=2\\x=-8\end{array} \right.\)
e) `sqrt(4x^2-4x+1)=3`
`=>sqrt((2x-1)^2)=3`
`=>|2x-1|=3`
`=>`\(\left[ \begin{array}{l}2x-1=3\\2x-1=-3\end{array} \right.\) `=>`\(\left[ \begin{array}{l}2x=4\\2x=-2\end{array} \right.\) `=>`\(\left[ \begin{array}{l}x=2\\x=-1\end{array} \right.\)
