The problem asks us to find the expression that is equivalent to $7(n + 3)$. We need to use the distributive property to simplify the given expression and then find the equivalent expression from the choices given.

1. Problem Description

The problem asks us to find the expression that is equivalent to $7(n + 3)$. We need to use the distributive property to simplify the given expression and then find the equivalent expression from the choices given.

2. Solution Steps

We need to simplify $7(n + 3)$. We will use the distributive property, which states that $a(b + c) = ab + ac$.

Applying the distributive property:

$7(n + 3) = 7*n + 7*3$

$7(n + 3) = 7n + 21$

Now we look at the options provided:

10n

21n + 7

7n + 21

21n

The expression that matches our simplified expression is $7n + 21$.

3. Final Answer

7n + 21