3x-9>-2x+x+12
3x-9>-x+12
3x - 9 + x -12 > 0
\(4x-21>0\)
\(\Leftrightarrow4x>21\Leftrightarrow x>\dfrac{21}{4}\)
Đúng 4
Bình luận (1)
\(3x-9>-2x+12\)
\(\Leftrightarrow3x+2x>12+9\)
\(\Leftrightarrow5x>21\)
\(\Leftrightarrow x>\dfrac{21}{5}\)
Vậy \(S=\left\{x|x>\dfrac{21}{5}\right\}\)
Đúng 8
Bình luận (1)
