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$4x^{2}-12x+5=0$

⇔ $4x^{2}-2x-10x+5=0$

⇔ $2x(2x-1)^{}-5(2x-1)=0$

⇔ $(2x-1)(2x-5)=0^{}$ 

⇔ \(\left[ \begin{array}{l}2x-1=0\\2x-5=0\end{array} \right.\) 

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

Chúc bạn học tốt !!!!!