x.(x+1/2)-1/5x-1/10=0 Help pls

`x(x+1/2)-1/5x-1/10=0`

`=>x(x+1/2)-(1/5x+1/10)=0`

`=>x(x+1/2)-1/5(x+1/2)=0`

`=>(x-1/5)(x+1/2)=0`

`=>` $\left[ \begin{array}{l}x-\dfrac{1}{5}=0\\x+\dfrac{1}{2}=0\end{array} \right.$

`=>` \(\left[ \begin{array}{l}x=\dfrac{1}{5}\\x=-\dfrac{1}{2}\end{array} \right.\) 

Vậy `x\in{1/5;-1/2}`

$\boxed{\bullet\text{ Áp dụng :}\\AB=0⇒\left[ \begin{array}{l}A=0\\B=0\end{array} \right.}$