Question: Select the expressions that are equivalent to $2(7m + 7) + 9$.
$2(7 + 7m) + 9$
$23m + 14$
$2(6m + m + 7) + 9$
$(7m + 7)2 + 9$
1. **State the problem:** We need to find which expressions are equivalent to $$2(7m + 7) + 9$$.
2. **Start by simplifying the original expression:**
$$2(7m + 7) + 9 = 2 \times 7m + 2 \times 7 + 9 = 14m + 14 + 9$$
3. **Combine like terms:**
$$14m + 14 + 9 = 14m + 23$$
4. **Check each given expression for equivalence:**
- Expression 1: $$2(7 + 7m) + 9$$
Rewrite inside parentheses: $$7 + 7m = 7m + 7$$ (commutative property)
So this is the same as the original expression, which simplifies to $$14m + 23$$.
- Expression 2: $$23m + 14$$
This is $$23m + 14$$, which is not equal to $$14m + 23$$.
- Expression 3: $$2(6m + m + 7) + 9$$
Simplify inside parentheses: $$6m + m = 7m$$, so it becomes $$2(7m + 7) + 9$$, which is the original expression.
- Expression 4: $$(7m + 7)2 + 9$$
Rewrite as $$2(7m + 7) + 9$$, which is the original expression.
5. **Conclusion:** Expressions 1, 3, and 4 are equivalent to the original expression $$2(7m + 7) + 9$$.
**Final answer:** The equivalent expressions are:
- $$2(7 + 7m) + 9$$
- $$2(6m + m + 7) + 9$$
- $$(7m + 7)2 + 9$$