\(\left|B\right|\)+3<2x-1
\(\Leftrightarrow\)\(\left[{}\begin{matrix}B+3< 2x-1\\-B+3< 2X-1\end{matrix}\right.\)
+ B+3<2x-1
\(\Leftrightarrow\)\(\dfrac{4-3x}{4}+3< 2x-1\)
\(\Leftrightarrow\dfrac{4-3x}{4}+\dfrac{12}{4}< 2x-1\)
\(\Leftrightarrow4-3x+12< 2x-1\)
\(\Leftrightarrow16-3x< 2x-1\)
\(\Leftrightarrow-5x< -17\)
\(\Leftrightarrow x>\dfrac{17}{5}\)
+ -B+3<2x-1
\(\Leftrightarrow\)\(\dfrac{-4+3x}{-4}\)+3<2x-1
\(\Leftrightarrow\dfrac{-4+3x}{-4}+\dfrac{-12}{-4}< 2x-1\)
\(\Leftrightarrow-4+3x-12< 2x-1\)
\(\Leftrightarrow x< 15\)
Vậy:ĐK của x để \(\left|B\right|+3< 2x-1\)
B=\(\dfrac{4-3x}{4}\)
\(\left(x|x>\dfrac{17}{5};x< 15\right)\)
