Đáp án:
a) \(\left[ \begin{array}{l}
x = 4\\
x = \dfrac{7}{2}
\end{array} \right.\)
b) x=2
Giải thích các bước giải:
\(\begin{array}{l}
a)4 - x = 2{\left( {x - 4} \right)^2}\\
\to 2{\left( {x - 4} \right)^2} + x - 4 = 0\\
\to \left( {x - 4} \right)\left( {2\left( {x - 4} \right) + 1} \right) = 0\\
\to \left[ \begin{array}{l}
x - 4 = 0\\
2x - 8 + 1 = 0
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = 4\\
x = \dfrac{7}{2}
\end{array} \right.\\
b)4{x^2}\left( {x - 2} \right) + 2x - 4 = 0\\
\to 4{x^2}\left( {x - 2} \right) + 2\left( {x - 2} \right) = 0\\
\to \left( {x - 2} \right)\left( {4{x^2} + 2} \right) = 0\\
\to x - 2 = 0\left( {do:4{x^2} + 2 > 0\forall x} \right)\\
\to x = 2
\end{array}\)
