Đáp án:
a, `(x² - 1)(2y + 4) = 0`
⇒ \(\left[ \begin{array}{l}x² - 1 = 0\\2y + 4 =0\end{array} \right.\)
⇒\(\left[ \begin{array}{l}x²=1\\2y = -4\end{array} \right.\)
⇒\(\left[ \begin{array}{l}x= ±1\\y = -2\end{array} \right.\)
b, `| 2x - 1| - 3 =0`
`| 2x - 1| = 0 + 3 = 3`
⇒\(\left[ \begin{array}{l}2x - 1 = 3\\2x - 1 = -3\end{array} \right.\)
⇒\(\left[ \begin{array}{l}2x = 4\\2x = -2\end{array} \right.\)
⇒\(\left[ \begin{array}{l}x=2\\x=-1\end{array} \right.\)
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