which expression shows 7 +21 writte as a product of two factors

To express \( 7 + 21 \) as a product of two factors, we first simplify \( 7 + 21 \):

\[
7 + 21 = 28
\]

Now, we need to find an expression among the options that simplifies to 28.

Let's evaluate each option:

A) \( 3(3 + 7) = 3 \times 10 = 30 \)

B) \( 3(1 + 7) = 3 \times 8 = 24 \)

C) \( 7(3 + 3) = 7 \times 6 = 42 \)

D) \( 7(1 + 3) = 7 \times 4 = 28 \)

The correct answer is:

**D - \( 7(1 + 3) \)**, which equals 28.