Equivalent Expression F08Cdc

1. **State the problem:** We want to find which expression is equivalent to $$a + (c + 7)$$. 2. **Recall the associative property of addition:** It states that for any numbers $x, y, z$, we have $$x + (y + z) = (x + y) + z$$. 3. **Apply the associative property:** Using this property, $$a + (c + 7) = (a + c) + 7$$. 4. **Check the options:** - $7 a c$ is not a valid addition expression. - $a - (c + 7)$ is subtraction, not addition. - $(c + 7) - a$ is subtraction, not addition. - $(a + c) + 7$ matches our simplified expression. 5. **Conclusion:** The expression equivalent to $$a + (c + 7)$$ is $$(a + c) + 7$$.