Đáp án:
$\begin{array}{l}
a){\left( {x + 3} \right)^2} + {\left( {x - 2} \right)^2} = 2x\left( {x + 2} \right)\\
\Rightarrow {x^2} + 6x + 9 + {x^2} - 4x + 4 = 2{x^2} + 4x\\
\Rightarrow 2{x^2} + 2x + 13 - 2{x^2} - 4x = 0\\
\Rightarrow - 2x + 13 = 0\\
\Rightarrow 2x = 13\\
\Rightarrow x = \frac{{13}}{2}\\
b){\left( {2x - 1} \right)^2} - 4x\left( {x - 3} \right) = 5\\
\Rightarrow 4{x^2} - 4x + 1 - 4{x^2} + 12x = 5\\
\Rightarrow 8x = 4\\
\Rightarrow x = \frac{1}{2}\\
d){x^2} - 4x - 77 = 0\\
\Rightarrow {x^2} - 4x + 4 - 4 - 77 = 0\\
\Rightarrow \left( {{x^2} - 4x + 4} \right) - 81 = 0\\
\Rightarrow {\left( {x - 2} \right)^2} - {9^2} = 0\\
\Rightarrow \left( {x - 2 - 9} \right)\left( {x - 2 + 9} \right) = 0\\
\Rightarrow \left[ \begin{array}{l}
x - 11 = 0\\
x + 7 = 0
\end{array} \right. \Rightarrow \left[ \begin{array}{l}
x = 11\\
x = - 7
\end{array} \right.
\end{array}$
Em chia nhỏ câu hỏi ra nhé
