Đáp án:
c) \(x = \dfrac{1}{2}\)
Giải thích các bước giải:
\(\begin{array}{l}
C1)\\
b)\left( {x - 3} \right)\left( {2x + 5} \right) = 0\\
\to \left[ \begin{array}{l}
x - 3 = 0\\
2x + 5 = 0
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = 3\\
x = - \dfrac{5}{2}
\end{array} \right.\\
c){x^2} - 2x + 1 = {x^2}\\
\to 2x = 1\\
\to x = \dfrac{1}{2}\\
d){x^2} - 2x - 3x + 6 = 0\\
\to x\left( {x - 2} \right) - 3\left( {x - 2} \right) = 0\\
\to \left( {x - 2} \right)\left( {x - 3} \right) = 0\\
\to \left[ \begin{array}{l}
x = 2\\
x = 3
\end{array} \right.
\end{array}\)
