Given the expression;
[tex]3x\text{ = 12}[/tex]We want to determine whether x = 4 is a solution. This is as shown below;
[tex]\begin{gathered} 3x\text{ = 12} \\ \text{divide both sides by 3} \\ \frac{3x}{3}=\frac{12}{3} \\ x=\text{ 4} \end{gathered}[/tex]Since the value of x gotten is 4, hence it is TRUE that x = 4 is a solution.