ANSWER:
The value of x is 4
STEP-BY-STEP EXPLANATION:
We have the following system of equations
[tex]\begin{gathered} y=6x+9 \\ y=12x-15 \end{gathered}[/tex]
Now, we solve the system by means of the equalization method
[tex]\begin{gathered} 6x+9=12x-15 \\ \end{gathered}[/tex]
solving for x
[tex]\begin{gathered} 12x-6x=9+15 \\ 6x=24 \\ x=\frac{24}{6} \\ x=4 \end{gathered}[/tex]
