`2x³+5x² -3x=0`
`<=>x(2x^2+5x -3)=0`
`<=>x[(2x^2-x)+(6x -3)]=0`
`<=>x[x(2x-1)+3(2x -1)]=0`
`<=>x(2x-1)(x +3)=0`
`<=>`\(\left[ \begin{array}{l}x=0\\x=\cfrac12\\x=-3\end{array} \right.\)
`7x² +13x-2=0 `
`<=>(7x² +14x)+(-x-2)=0 `
`<=>7x(x +2)-(x+2)=0 `
`<=>(x+2)(7x-1)=0`
`<=>`\(\left[ \begin{array}{l}x=-2\\x=\cfrac17\end{array} \right.\)