Answer:
Step-by-step explanation:
To subtract -7a^2+3a-9 from 5a^2-6-4
We have
5a^2-10--7a^2+3a-9
5a^2-10+7a^2+3a-9
Collect like terms
12a^2+3a-10-9
12a^2+3a-19
