Bài giải:
a) 5x(x -2000) - x + 2000 = 0
5x(x -2000) - (x - 2000) = 0
(x - 2000)(5x - 1) = 0
Hoặc 5x - 1 = 0 => 5x = 1 => x =
Vậy x = ; x = 2000
b) x3 – 13x = 0
x(x2 - 13) = 0
Hoặc x = 0
Hoặc x2 - 13 = 0 => x2 = 13 => x = ±√13
Vậy x = 0; x = ±√13
a) 5x(x-2000)-x+2000=0
5x(x-2000)-(x-2000)=0
(x-2000)(5x-1)=0
\(\Leftrightarrow\) x-2000=0 hoặc 5x-1=0
\(\Leftrightarrow\) x=2000 hoặc x=\(\dfrac{1}{5}\)
b) \(x^3-13x=0\)
\(x\left(x^2-13\right)=0\)
\(\Leftrightarrow x=0\) hoặc \(x^2-13=0\)
\(\Leftrightarrow x=0\) hoặc \(x=13\) hoặc \(x=-13\)
a) 5x(x -2000) - x + 2000 = 0
5x(x -2000) - (x - 2000) = 0
(x - 2000)(5x - 1) = 0
Hoặc 5x - 1 = 0 => 5x = 1 => x = 1515
Vậy x = 1515; x = 2000
b) x3 – 13x = 0
x(x2 - 13) = 0
Hoặc x = 0
Hoặc x2 - 13 = 0 => x2 = 13 => x = ±√13
Vậy x = 0; x = ±√13
a)5x(x-2000) -x -2000 =0
<=>5x(x -2000) - (x-2000)=0
<=>x-2000=0
hoặc 5x=1
<=>x=2000
hoặc x=\(\dfrac{1}{5}\)
b)x3-13x= 0
<=>x(x2-13)=0
<=>x=0
hoặc x2=13
<=>x=0
hoặc x= \(\sqrt{13}\)
a)\(5x\left(x-2000\right)-x+2000=0\)
\(\Rightarrow5x\left(x-2000\right)+\left(-x+2000\right)=0\)
\(\Rightarrow5x\left(x-2000\right)-\left(x-2000\right)=0\)
\(\Rightarrow\left(5x-1\right)\left(x-2000\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}5x-1=0\\x-2000=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\dfrac{1}{5}\\x=2000\end{matrix}\right.\)
Vậy...........
b)\(x^3-13x=0\)
\(x\left(x^2-13\right)=0\)
\(x\left[x^2-\left(\sqrt{13}\right)^2\right]=0\)
\(\Rightarrow x\left(x-\sqrt{13}\right)\left(x+\sqrt{13}\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=0\\x-\sqrt{13}=0\Rightarrow\\x+\sqrt{13}=0\end{matrix}\right.\left[{}\begin{matrix}x=0\\x=\sqrt{13}\\x=-\sqrt{13}\end{matrix}\right.\)
Vậy...............
