`3x+7=0`
`<=>3x=-7`
`<=>x=-7/3`
Vậy `S={-7/3}`
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`2x(x-2)+2x(5-3x)=0`
`<=>2x(x-2+5-3x)=0`
`<=>2x(3-2x)=0`
`@TH1:2x=0<=>x=0`
`@TH2: 3-2x=0<=>2x=3<=>x=3/2`
Vậy `S={0;3/2}`
3x+7=0
\(\Leftrightarrow3x=-7\Leftrightarrow x=-\dfrac{7}{3}\)
2x(x-2)+2x(5-3x)=0
\(\Leftrightarrow2x\left(x-2+5-3x\right)=0\)
\(\Leftrightarrow2x\left(-2x+3\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}2x=0\\-2x=-3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{-3}{-2}=\dfrac{3}{2}\end{matrix}\right.\)
3x + 7 = 0
\(\Leftrightarrow\) 3x = -7
\(\Leftrightarrow\) x = -7/3
2x(x - 2) + 2x(5 - 3x) = 0
\(\Leftrightarrow\) 2x(x - 2 + 5 - 3x) = 0
\(\Leftrightarrow\) 2x(-2x + 3) = 0
\(\Leftrightarrow\left[{}\begin{matrix}2x=0\\-2x+3=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{3}{2}\end{matrix}\right.\)
\(\Leftrightarrow3x=-7\Leftrightarrow x=-\dfrac{7}{3}\)
\(\Leftrightarrow2x\left(x-2+5-3x\right)=0\)
\(\Leftrightarrow2x\left(3-2x\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}2x=0\\3-2x=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\-2x=-3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{3}{2}\end{matrix}\right.\)
3x+7=0
<=> 3x = -7
<=> x = -7/3
Vậy nghiệm của phương trình đã cho là x=-7/3
2x(x - 2) + 2x(5 - 3x) = 0
⇔ 2x(x - 2 + 5 - 3x) = 0
⇔ 2x(-2x + 3) = 0
<=> \(\left[{}\begin{matrix}2x=0\\-2x+3=0\end{matrix}\right.\)
<=>\(\left[{}\begin{matrix}x=0\\x=\dfrac{3}{2}\end{matrix}\right.\)
Vậy tập nghiệm của phương trình là \(\left\{0,\dfrac{3}{2}\right\}\)
