Step-by-step explanation:
First you add up 3c and 7c as they have the same parameter. That makes 10c. Then calculate 5d-9d which equals -4d. You can change the order of 5d-9d in a way that you would reduce the larger number from the smaller number so that you could calculate it easily like that. The final Ander 2ould be 10c-4d
