Answer:
−2x + 21
Without parenthesis, the answer would be different.
Step-by-step explanation:
1) Distribute the Negative Sign:
4x + 9 + −1(6x−12)
4x + 9 + −1(6x) + (−1)(−12)
4x + 9 + −6x + 12
2) Combine Like Terms:
4x + 9 + −6x + 12
(4x + −6x) + (9 + 12)
−2x + 21
