Answer:
9c + 5x + 3y + 13
Explanation:
you can't combine any of the numbers wwith variables because the variables aren't the same but you can combine the other numbers (8, -2, 7)
8 - 2 = 6
6 + 7 = 13
put the equation back together but instead replace the 8, -2, and 7 with 13 giving you
9c + 5x + 3y +13