How do you express x + x + x + x in terms of multiplication?

To express the sum x + x + x + x in terms of multiplication, you need to recognize that you are adding the variable x a total of four times. In algebra, when you add the same number multiple times, it can be simplified using multiplication.

In this case, you have:

x + x + x + x = 4 times x = 4x.

This shows that the sum is equivalent to multiplying the number x by 4. Therefore, representing the expression as a product gives you 4x, which corresponds to the third choice.

Understanding this concept is key in algebra, as it allows for simplification of expressions and makes calculations more manageable. Each time you see a repeated addition of the same variable, it can be directly converted into a multiplication expression, simplifying the problem significantly.