a) \(5x\left(1-2x\right)-3x\left(x+18\right)=0\)
\(\Rightarrow5x-10x^2-3x^2-54x=0\)
\(\Leftrightarrow-49x-13^2=0\)
\(\Leftrightarrow-x\left(49+13x\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\49+13x=0\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=0\\x=-\dfrac{49}{13}\end{matrix}\right.\)
Vậy \(x_1=0;x_2=-\dfrac{49}{13}\)
b) \(5x-3\left\{4x-2\left[4x-3\left(5x-2\right)\right]\right\}=182\)
\(\Rightarrow5x-3\left[4x-2\left(4x-15x+6\right)\right]=182\)
\(\Leftrightarrow5x-3\left[4x-2\left(-11x+6\right)\right]=182\)
\(\Leftrightarrow5x-3\left(4x+22x-12\right)=182\)
\(\Leftrightarrow5x-3\left(26x-12\right)=182\)
\(\Leftrightarrow5x-78x+36=182\)
\(\Leftrightarrow-73x+36=182\)
\(\Leftrightarrow-73x=182-36\)
\(\Leftrightarrow-73x=146\)
\(\Rightarrow x=146:\left(-73\right)\)
\(\Rightarrow x=-2\)
Vậy \(x=-2\)
