By following the order of operations, we need to evaluate first the multiplication of 3 and (4x+3) by using the distributive property.
[tex]\begin{gathered} 3(4x+3)-12\text{ (given)} \\ \\ \text{apply the distributive property} \\ =(3\cdot4x+3\cdot3)-12 \\ =12x+9-12 \end{gathered}[/tex]After that, combine like terms, we see from the previous solution that 12x has no other like terms, and it will remain as is. 9 and 12 however are both constant, and should be simplified
[tex]\begin{gathered} 12x+9-12 \\ =12x-3 \end{gathered}[/tex]Therefore, 3(4x+3) - 12, when simplified is 12x - 3.
