a.\(x:\left(\dfrac{1}{7}-\dfrac{3}{14}\right)=-4\dfrac{3}{8}\)
\(x:-\dfrac{1}{14}=-\dfrac{35}{8}\)
\(x=-\dfrac{35}{8}.-\dfrac{1}{14}\)
\(x=\dfrac{5}{16}\)
b.\(\dfrac{1}{3}x+\dfrac{2}{5}x-\dfrac{2}{5}=0\)
\(\dfrac{11}{15}x=\dfrac{2}{5}\)
\(x=\dfrac{2}{5}:\dfrac{11}{15}\)
\(x=\dfrac{6}{11}\)
c.\(x^3-\dfrac{1}{25}x=0\)
\(x\left(x^2-\dfrac{1}{25}\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=0\\x^2-\dfrac{1}{25}=0\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x=0\\x=\pm\dfrac{1}{5}\end{matrix}\right.\)
:> xin hai câu cúi hoy , tại bị nghiện mấy câu kiur v á 🥺
`b)1/(3)x+2/(5)x-2/5=0`
`x.(1/3+2/5)-2/5=0`
`x.(11)/15-2/5=0`
`11/(15)x=0+2/5`
`11/(15)x=2/5`
`x=2/5:11/15`
`x=2/(5).(15)/11`
`x=6/11`
`c)`
`x^{3}-1/(25)x=0`
`<=>x(x^{2}-1/25)=0`
`<=>[(x=0),(x^{2}-1/25=0):]`
`<=>` $\left[\begin{matrix} x=0\\ x^{2}=\dfrac{1}{25}\end{matrix}\right.$
`<=>`$\left[\begin{matrix} x=0\\ x^{2}=(+-\dfrac{1}{5})\end{matrix}\right.$
Vậy `x ={0;1/5;(-1/5)}`
