If 3(y + 3y) = 12, what is the value of y?

To find the value of (y) in the equation (3(y + 3y) = 12), it's important to first simplify the expression inside the parentheses. This can be done by combining like terms. The expression (y + 3y) simplifies to (4y).

Now, substituting back into the equation gives:

[ 3(4y) = 12 ]

Next, we can simplify the left side of the equation:

[ 12y = 12 ]

To isolate (y), divide both sides of the equation by 12:

[ y = \frac{12}{12} ]

This simplifies to:

[ y = 1 ]

Thus, the value of (y) is (1.0), which aligns with the correct answer. Understanding how to simplify expressions and isolate variables is crucial in algebra, and in this case, recognizing the combination of terms in the parentheses led to the solution.