First define the variables:
c = amount of children
a = amount of adults
Next create the equations to satisfy the conditions:
1) Total group is 12 people:

2) Total cost is $100 with adults costing $10 and children being $6:

3cd^2(6cd + 14cd^2)
18cd^3 + 42cd^4
Step-by-step explanation:

Answer:
12h + 6k
Step-by-step explanation:
3 times 4h = 12h
3 times 2k = 6k