a ) \(5-7x\ge2x+14\)
\(\Leftrightarrow-7x-2x\ge14-5\)
\(\Leftrightarrow-9x\ge9\)
\(\Leftrightarrow x\le-1\)
Vậy bất phương trình có nghiệm \(x\le1\)
b ) \(\dfrac{1,5-x}{5}< \dfrac{4x+5}{2}\)
\(\Leftrightarrow2\left(1,5-x\right)< 5\left(4x+5\right)\)
\(\Leftrightarrow3-2x< 20x+25\)
\(\Leftrightarrow-2x-20x< 25-3\)
\(\Leftrightarrow-22x< 22\)
\(\Leftrightarrow x>-1\)
Vậy bất phương trình có nghiệm \(x>-1\)
Tick nha
a) 5 - 7x \(\ge\) 2x + 14
\(\Leftrightarrow\) -7x -2x \(\ge\) -5 + 14
\(\Leftrightarrow\) -9x \(\ge\) 9
\(\Leftrightarrow\) x \(\le\) -1
b) \(\dfrac{1,5-x}{5}< \dfrac{4x+5}{2}\)
\(\Leftrightarrow\) \(2\left(1,5-x\right)\) \(< 5\left(4x+5\right)\)
\(\Leftrightarrow\) \(3-2x\)\(< 20x+25\)
\(\Leftrightarrow\) \(-2x-20x< -3+25\)
\(\Leftrightarrow\) \(-22x< 22\)
\(\Leftrightarrow\) \(x>-1\)