a) 5x( x - 2) + 3x - 6 =0
(=) 5x( x - 2) + 3( x - 2) = 0
(=) ( x - 2)( 5x + 3) =0
Vậy , x = 2 ; x = \(-\dfrac{3}{5}\)
b) x3 - 9x = 0
(=) x( x2 - 32) = 0
(=) x( x - 3)( x + 3) =0
Vậy , x = 0 ; x = 3 ; x = -3
a \(5x\left(x-2\right)+3x-6=0\)
\(\Rightarrow5x\left(x-2\right)+3\left(x-2\right)=0\)
\(\Rightarrow\left(x-2\right)\left(5x+3\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x-2=0\\5x+3=0\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=2\\x=\dfrac{-3}{5}\end{matrix}\right.\)
b, \(x^3-9x=0\)
\(\Rightarrow x\left(x^2-9\right)=0\)
\(\Rightarrow x\left(x-3\right)\left(x+3\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=0\\x-3=0\\x+3=0\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=0\\x=3\\x=-3\end{matrix}\right.\)
\(a,5x\left(x-2\right)+3x-6=0\)
\(\Rightarrow5x\left(x-2\right)+3\left(x-2\right)=0\)
\(\Rightarrow\left(x-2\right)\left(5x-3\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x-2=0\\5x-3=0\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=2\\x=\dfrac{3}{5}\end{matrix}\right.\)
\(b,x^3-9x=0\)
\(\Rightarrow x\left(x^2-9\right)=0\)
\(\Rightarrow x\left(x^2-3^2\right)=0\)
\(\Rightarrow x\left(x-3\right)\left(x+3\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=0\\x-3=0\\x+3=0\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=0\\x=3\\x=-3\end{matrix}\right.\)
a ) \(5x\left(x-2\right)+3x-6=0\)
\(\Leftrightarrow5x\left(x-2\right)+3\left(x-2\right)=0\)
\(\Leftrightarrow\left(x-2\right)\left(5x+3\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-2=0\\5x+3=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=2\\x=-\dfrac{3}{5}\end{matrix}\right.\)
Vậy.............
b ) \(x^3-9x=0\)
\(\Leftrightarrow x\left(x^2-9\right)=0\)
\(\Leftrightarrow x\left(x-3\right)\left(x+3\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x-3=0\\x+3=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=0\\x=3\\x=-3\end{matrix}\right.\)
Vậy............
