#KhanhHuyen2006 - Xin câu trả lời hay nhất
`a) 2 |3x - 1| + 5 = 27`
`-> 2 |3x - 1| = 22`
`-> |3x - 1| = 11`
`->` \(\left[ \begin{array}{l}3x - 1 = 11\\3x - 1 = -11\end{array} \right.\)
`->` \(\left[ \begin{array}{l}3x = 12\\3x = -10\end{array} \right.\)
`->` \(\left[ \begin{array}{l}x=4\\x=-10/3\end{array} \right.\)
`b) (2x + 5) (x^2 - 16) = 0`
`->` \(\left[ \begin{array}{l}2x + 5 = 0\\x^2 - 16 = 0\end{array} \right.\)
`->` \(\left[ \begin{array}{l}2x = -5\\x^2 = 16\end{array} \right.\)
`->` \(\left[ \begin{array}{l}x=-5/2\\x = ±4\end{array} \right.\)
`c) (4x + 8) (10 - 3x) < 0`
`->` \(\left[ \begin{array}{l}4x + 8 > 0\\10 - 3x < 0\end{array} \right.\)
`->` \(\left[ \begin{array}{l}4x > -8\\3x < 10\end{array} \right.\)
`->` \(\left[ \begin{array}{l}x > -2\\x < 10/3\end{array} \right.\)
`-> -2 < x < 10/3`
`d) (3x + 9) (5 - x) < 0`
`->` \(\left[ \begin{array}{l}3x + 9 > 0\\5 - x < 0\end{array} \right.\)
`->` \(\left[ \begin{array}{l}3x > -9\\x < 5\end{array} \right.\)
`->` \(\left[ \begin{array}{l}x>-3\\x < 5\end{array} \right.\)
`-> -3 < x < 5`
