How do you simplify the expression 3(x + 4)?

To simplify the expression 3(x + 4), you need to apply the distributive property, which states that a(b + c) = ab + ac. In this context, you distribute the 3 to both terms inside the parentheses.

First, you take the term x inside the parentheses and multiply it by 3, which gives you 3x. Next, you take the constant 4 and also multiply it by 3, resulting in 12.

Putting it all together, the expression simplifies to 3x + 12. This is why the correct simplification of 3(x + 4) leads to the result 3x + 12.