2 câu trả lời
`(9x+1).(3x-2)-2x.(2-3x)=0`
`=>(9x+1).(3x-2)+2x.(3x-2)=0`
`=>(3x-2).(9x+1+2x)=0`
`=>(3x-2).(7x+1)=0`
`=>`\(\left[ \begin{array}{l}3x-2=0\\7x+1=0\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}3x=2\\7x=-1\end{array} \right.\)
`=>`\(\left[ \begin{array}{l}x=\dfrac{2}{3}\\x=-\dfrac{1}{7}\end{array} \right.\)
Vậy `x in {\frac{2}{3}; -\frac{1}{7}}`
Đáp án+Giải thích các bước giải:)
@danggiabao0
`(9x+1)`.`(3x-2)`-`2x`.`(2-3x)`=`0`
⇒`(3x-2)`.`(9x+1+2x)`=`0`
⇒`(3x-2)`.`(7x+1)`=`0`
⇒`3x-2`=`0`
⇒`7x+1`=`0`
⇒x=`2/3`
⇒y=`{-1}/7`
