Tìm x biết: 10x+8-4x(5x +4)=0

Tìm $x$ biết:$10x+8-4x\left(5x+4\right)=0$

$10x+8-4x\left(5x+4\right)=0$

$\iff 2\left(5x+4\right)-4x\left(5x+4\right)=0$

$\iff \left(2-4x\right)\left(5x+4\right)=0$

$\iff \left[\begin{array}{l}2-4x=0\\ 5x+4=0\end{array}\right.\iff \left[\begin{array}{l}4x=2\\ 5x=-4\end{array}\right.\iff \left[\begin{array}{l}x=\frac{1}{2}\\ x=-\frac{4}{5}\end{array}\right.$

Vậy $x=\frac{1}{2};x=-\frac{4}{5}.$