Answer:
10c - 4d
Step-by-step explanation:
1. Rearrange the problem so similar variables are closer together
3c + 7c + 5d - 9d
2. Simplify the problem by adding like terms
3c + 7c = 10c
5d - 9d = -4d
3. Rewrite the problem so the variables are in ABC order
10c - 4d
Hope this helps :)
