x < -6
Explanation:
[tex]\begin{gathered} 3x\text{ + 12 < x} \\ \text{collect like terms:} \\ 3x\text{ - x + 12 < 0} \end{gathered}[/tex]Solve the expression:
[tex]\begin{gathered} 2x\text{ + 12 < 0} \\ Bring\text{ the constant to the other side} \\ 2x\text{ < -12} \\ \text{Divide through by the coefficient of x (2)} \\ \frac{2x}{2}\text{ <}\frac{-12}{2} \\ x\text{ < -6} \end{gathered}[/tex]