Final answer:
The equivalent expression for 1/3(12x + 6x - 21) is 6x - 7.
Step-by-step explanation:
To write an equivalent expression for 1/3(12x + 6x - 21), you need to distribute the fraction 1/3 across each term in the parentheses.
This means you multiply 1/3 by each term separately.
- 1/3 × 12x = 4x
- 1/3 × 6x = 2x
- 1/3 × -21 = -7
Now, combine these results to get the equivalent expression:
4x + 2x - 7
Lastly, combine like terms (4x and 2x) to further simplify:
6x - 7