\(a)2x-3=4x+6\\ \Rightarrow2x=-9\\ \Rightarrow x=-\dfrac{9}{2}\\ c)x\left(x-1\right)+x\left(x+3\right)=0\\ \Rightarrow x^2-x+x^2+3x=0\\ \Rightarrow2x^2+2x=0\\ \Rightarrow2x\left(x+1\right)=0\\ \Rightarrow\left[{}\begin{matrix}2x=0\\x+1=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=0\\x=-1\end{matrix}\right.\)
`a)2x-3=4x+6`
`<=>2x-4x=6+3`
`<=>-2x=9`
`<=>x=-9/2`
Vậy `S={-9/2}`
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
`c)x(x-1)+x(x+3)=0`
`<=>x(x-1+x+3)=0`
`<=>x(2x+2)=0`
`@TH1:x=0`
`@TH2:2x+2=0<=>2x=-2<=>x=-1`
Vậy `S={-1;0}`
aa)2x – 3 = 4x + 6
\(=>2x-4x=6+3\)
\(=>-2x=9\)
\(=>x=-\dfrac{9}{2}\)
c) x(x – 1) + x(x + 3) = 0
\(=>x\left(x-1+x+3\right)=0\)
\(x\left(2x+2\right)=0\)
\(=>\left[{}\begin{matrix}x=0\\2x=-2\end{matrix}\right.=>\left[{}\begin{matrix}x=0\\x=-1\end{matrix}\right.\)
a, `2x - 3 = 4x + 6`
`2x + 9 = 0`
`=> x = -9/2`.
b, `x(x-1) + x(x+3) = 0`
`=> 2x^2 + 2x = 0`
`=> 2(x(x+1)) = 0`
`=> x = 0`
`x + 1 = 0`
`=> x = 0`
`x = -1`.
