Question

which pair of expressions below are equivalent
9x+7x and 16x
9x+7x and 16x2
9(7x-5) and 63x - 5
9x-7y and 7y - 9x

Answer 1

To determine which pair of expressions are equivalent, let's evaluate each pair:

1. **9x + 7x and 16x**:
- \( 9x + 7x = 16x \)
- **Equivalent**

2. **9x + 7x and 16x²**:
- \( 9x + 7x = 16x \)
- \( 16x \neq 16x^2 \)
- **Not Equivalent**

3. **9(7x - 5) and 63x - 5**:
- Distributing in the first expression:
- \( 9(7x) - 9(5) = 63x - 45 \)
- **Not Equivalent (63x - 45 is not equal to 63x - 5)**

4. **9x - 7y and 7y - 9x**:
- Rearranging the second expression gives \( -9x + 7y \), which is not the same as \( 9x - 7y \).
- **Not Equivalent**

The only pair that is equivalent is the first pair: **9x + 7x and 16x**.