Đáp án:
(5-2x).(2x+7)=(2x-5).(2x+5)
⇔(5-2x).(2x+7)-(2x-5).(2x+5)=0
⇔(5-2x).(2x+7)+(5-2x).(2x+5)=0
⇔(5-2x)(2x+7+2x+5)=0
⇔(5-2x)(4x+12)=0
⇔(5-2x)4(x+3)=0
⇔(5-2x)(x+3)=0
⇔\(\left[ \begin{array}{l}5-2x=0\\x+3=0\end{array} \right.\)
⇔\(\left[ \begin{array}{l}-2x=-5\\x=-3\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=$\frac{5}{2}$ \\x=-3\end{array} \right.\)
Giải thích các bước giải:
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