Answer:

Step-by-step explanation:





Answer:
15
Step-by-step explanation:
18-x=3
18-3=x
18-3=15
Answer:
20%
Step-by-step explanation:
Answer:
You can tell because, as x increases/decreases, y increases/decreases at the same rate EACH TIME. This way, no matter how many times the proportions increase OR decrease, the ratio between x and y always stays the same.
4(2x raise to power 2-4-7x)