1)
\(2\sqrt{75}+3\sqrt{48}-4\sqrt{27}=2\sqrt{5^2.3}+3\sqrt{4^2.3}-4\sqrt{3^2.3}\)
\(=10\sqrt{3}+12\sqrt{3}-12\sqrt{3}=10\sqrt{3}\)
2)\(\left\{{}\begin{matrix}2x-y=8\\3x+2y=5\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}y=2x-8\\3x+4x-16=5\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}y=2x-8\\7x=5+16=21\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}y=2.3-8=-2\\x=3\end{matrix}\right.\)
3)`3x^2-7x+2=0`
`<=>3x^2-x-6x+2=0`
`<=>x(3x-1)-2(3x-1)=0`
`<=>(x-2)(3x-1)=0`
\(\Leftrightarrow\left[{}\begin{matrix}x-2=0\\3x=1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=2\\x=\dfrac{1}{3}\end{matrix}\right.\)
Vậy `S={2; 1/3 }`
