Evaluate the indefinite integral: \[ \int 12 d x=\square+C \]

Step 1 ：Evaluate the indefinite integral: \(\int 12 dx\)

Step 2 ：The integral of a constant is simply the constant times the variable of integration. In this case, the constant is 12 and the variable of integration is x.

Step 3 ：Therefore, the integral of 12 dx is 12x.

Step 4 ：We also need to add the constant of integration, C, to account for any constant term that may have been present in the original function before differentiation.

Step 5 ：The indefinite integral of 12 dx is \(\boxed{12x + C}\).