Answer:
3(x + 6) and 4x + 18 - x
Explanation:
Let's solve each option to see whether we would get 3x + 18:
✔️2x + 9 + 2x + 9
Add like terms
2x + 2x + 9 + 9
4x + 18
✔️3(x + 6)
3*x + 3*6
3x + 18 (it is an equivalent)
✔️4x + 18 - x
Add like terms
4x - x + 18
3x + 18 (it is an equivalent)
✔️2(4x + 9)
8x + 18
Therefore, the expressions 3(x + 6) and 4x + 18 - x are equivalent to 3x + 18