a,1 + 2(x - 1) > 3 - 2x
\(\Leftrightarrow\) 1 + 2x - 2 > 3 - 2x
\(\Leftrightarrow\) 2x + 2x > 3 - 1 + 2
\(\Leftrightarrow\) 4x > 4
\(\Leftrightarrow\) x > 1
Vậy bpt có no là S= {x|x >1}
b, 2 + \(\dfrac{2-3x}{5}\) \(\ge\) \(\dfrac{x+7}{2}\)
MTC là 10
\(\Leftrightarrow\) \(\dfrac{2.10}{10}\) + \(\dfrac{2\left(2-3x\right)}{10}\) + \(\dfrac{5\left(x+7\right)}{10}\)
\(\Leftrightarrow\) 20 + 2(2 - 3x) \(\ge\) 5(x + 7)
\(\Leftrightarrow\) 20 + 4 - 6x \(\ge\) 5x + 35
\(\Leftrightarrow\) -6x - 5x \(\ge\) 35 - 20 - 4
\(\Leftrightarrow\) -11x \(\ge\) 11
\(\Leftrightarrow\) x \(\le\) -1
Vậy bpt có no là S={x|x\(\le\) -1}