a)\(2x+3>3x-5\)
\(\Leftrightarrow2x-3x+3>-5\)
\(\Leftrightarrow-x+3>-5\)
\(\Leftrightarrow-x>-8\)
\(\Leftrightarrow x< 8\)
c)\(\left|2x-4\right|=3x+2\left(đk:x\ge-\dfrac{2}{3}\right)\)
\(\Leftrightarrow\left[{}\begin{matrix}2x-4=3x+2\left(đk:x\ge2\right)\\2x-4=-3x-2\left(đk:x< 2\right)\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-6\left(loai\right)\\x=\dfrac{2}{5}\left(tm\right)\end{matrix}\right.\)
a) 2x + 3 > 3x - 5
<=> 2x - 3x > -5 - 3
<=> -x > -8
<=> x<1
Vậy { x / x < 1 }
b) -4x - 7 \(\le\) 2x + 4
<=> -4x - 2x \(\le\) 4 + 7
<=> -6x \(\le\) 11
<=> x \(\ge\) \(-\dfrac{11}{6}\)
Vậy { x / x\(\ge-\dfrac{11}{6}\) }
c) \(\left|2x-4\right|\) = 3x +2
<=> \(\left[{}\begin{matrix}2x-4=3x+2\\4-2x=3x+2\end{matrix}\right.\)
+) Với 2x - 4 = 3x + 2 ( ĐK : x\(\ge\) 2 )
<=> 2x - 3x = 2 + 4
<=> -x = 6
<=> x = -6 ( Không T/M ĐK => Loại )
+) Với 4 - 2x = 3x + 2 ( ĐK : x < 2 )
<=> -2x - 3x = 2 - 4
<=> -5x = -2
<=> x = \(\dfrac{2}{5}\) ( T/M ĐK => Nhận )
Vậy S = { \(\dfrac{2}{5}\) }
