a,(3x-1)(-1/2x+5)=0 b,1/2x+2/3x-1=-8/3 (Tìm x) 09/11/2021 Bởi Adeline a,(3x-1)(-1/2x+5)=0 b,1/2x+2/3x-1=-8/3 (Tìm x)
a, Ta có: $\frac {3x-1}{\frac {-1}{2x}+5}=0$<=> $ \left[ \begin{array}{l}3x-1=0\\\frac {-1}{2x}+5=0\end{array} \right. $<=>$\left[ \begin{array}{l}x=\frac{1}{3}\\x=\frac{1}{10}\end{array} \right. $Vậy $\left[ \begin{array}{l}x=\frac{1}{3}\\x=\frac{1}{10}\end{array} \right. $ b, Ta có: $\frac {1}{2x} + \frac {2}{3x} -1= \frac {-8}{3}$ <=> $\frac {7x}{6x^{2}}-1= \frac {-8}{3}$ <=> $\frac {7x-6x^{2}}{6x^{2}}= \frac {-8}{3}$ <=> $21x-18x^{2}=-48x^{2}$ <=> $30x^{2}+21x=0$ <=> $\frac {-30}{21} = \frac {x}{x^{2}}$ <=> $x=-0,7$. Vậy $x=-0,7$ Bình luận
Đáp án: Giải thích các bước giải: `a,(3x-1)(-1/2x+5)=0` $=>\left[ \begin{array}{l}3x-1=0\\-1/2x+5=0\end{array} \right.$ $=>\left[ \begin{array}{l}x=1/3\\x=10\end{array} \right.$ `b,1/2x+2/3x-1=-8/3` `=>x(1/2+2/3)=-8/3+1` `=>7/6x=-5/3` `=>x=-10/7` Bình luận
a,
Ta có: $\frac {3x-1}{\frac {-1}{2x}+5}=0$
<=> $ \left[ \begin{array}{l}3x-1=0\\\frac {-1}{2x}+5=0\end{array} \right. $
<=>$\left[ \begin{array}{l}x=\frac{1}{3}\\x=\frac{1}{10}\end{array} \right. $
Vậy $\left[ \begin{array}{l}x=\frac{1}{3}\\x=\frac{1}{10}\end{array} \right. $
b,
Ta có: $\frac {1}{2x} + \frac {2}{3x} -1= \frac {-8}{3}$
<=> $\frac {7x}{6x^{2}}-1= \frac {-8}{3}$
<=> $\frac {7x-6x^{2}}{6x^{2}}= \frac {-8}{3}$
<=> $21x-18x^{2}=-48x^{2}$
<=> $30x^{2}+21x=0$
<=> $\frac {-30}{21} = \frac {x}{x^{2}}$
<=> $x=-0,7$.
Vậy $x=-0,7$
Đáp án:
Giải thích các bước giải:
`a,(3x-1)(-1/2x+5)=0`
$=>\left[ \begin{array}{l}3x-1=0\\-1/2x+5=0\end{array} \right.$
$=>\left[ \begin{array}{l}x=1/3\\x=10\end{array} \right.$
`b,1/2x+2/3x-1=-8/3`
`=>x(1/2+2/3)=-8/3+1`
`=>7/6x=-5/3`
`=>x=-10/7`