a: \(\dfrac{2x+1}{3}-\dfrac{3x-2}{2}\le3\)
\(\Leftrightarrow4x+2-9x+6\le18\)
\(\Leftrightarrow-5x\le10\)
hay x>=-2
b: \(5x^2-\left(4x^2-1\right)< =2x\)
\(\Leftrightarrow5x^2-4x^2+1-2x< =0\)
\(\Leftrightarrow\left(x-1\right)^2< =0\)
Dấu '=' xảy ra khi x=1