In the equation \( x^8 = 3(x + 4)^2 \), the expression that represents a product is:
3(x + 4)
This is because it involves the multiplication of the constants and the expression inside the parentheses.
The expression \( 3(x + 4)^2 \) also represents a product, but since the question specifies just one expression in the equation, \( 3(x + 4) \) is more straightforward as it shows the multiplicative relationship without the exponent.
So, the correct response is:
3(x + 4)