Answer:
Explanation:
Remark
There is an isolated plus sign in the middle so removing the brackets is going to allow you to collect like terms quickly and immediately.
Solution
12a^2 + 6a - 8 - 22a^2+ 12 - 15a Group like terms together in pairs.
12a^2- 22a^2 + 6a - 15a - 8 + 12 Combine like terms.
Answer
-10a^2 - 9a + 4