Question

a,-3+18=0

b,(2x-1)-x(2x-1)=0

Answer 1

\(a)-3x+18=0\\ \Leftrightarrow-3x=-18\\ \Leftrightarrow x=6\\ b)\left(2x-1\right)-x.\left(2x-1\right)=0\\ \Leftrightarrow\left(1-x\right)\left(2x-1\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}1-x=0\\2x-1=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=1\\x=\dfrac{1}{2}\end{matrix}\right.\)

Answer 2

Bạn xem lại đề câu `a`

`b,(2x-1)-x[x(2x-1)]=0`

`<=>(2x-1)-x^2(2x-1)=0`

`<=>(2x-1)(1-x^2)=0`

`<=>` $\left[\begin{matrix} x=\dfrac{1}{2}\\ x=+-1\end{matrix}\right.$

Vậy `S={1/2;+-1}`