\(3,\left(9-7x\right)\left(11-3x\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{9}{7}\\x=\dfrac{11}{3}\end{matrix}\right.\)
\(4,\left(7-14x\right)\left(x-2\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{2}\\x=2\end{matrix}\right.\)
\(5,\left(2x+1\right)\left(x-3\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{1}{2}\\x=3\end{matrix}\right.\)
Câu còn lại cũng tương tự
3) \(\left\{{}\begin{matrix}9-7x=0\\11-3x=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}-7x=-9\\-3x=-11\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{9}{7}\\x=\dfrac{11}{3}\end{matrix}\right.\)
4)\(\left\{{}\begin{matrix}7-14x=0\\x-2=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}-14x=-7\\x=2\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{7}{14}\\x=2\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{1}{2}\\x=2\end{matrix}\right.\)
5)\(\left\{{}\begin{matrix}2x-1=0\\x-3=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}2x=1\\x=3\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{1}{2}\\x=3\end{matrix}\right.\)
6)\(\left\{{}\begin{matrix}8-3x=0\\-3x+5=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}-3x=-8\\-3x=-5\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{8}{3}\\x=\dfrac{5}{3}\end{matrix}\right.\)
7)\(\left\{{}\begin{matrix}16-8x=0\\2-6x=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}-8x=-16\\-6x=-2\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=2\\x=\dfrac{1}{3}\end{matrix}\right.\)
8)\(\left\{{}\begin{matrix}x+4=0\\6x-12=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=-4\\6x=12\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=-4\\x=2\end{matrix}\right.\)
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