The answer is 8 hope this helps all u have to do is figure out what two numbers added togher give you 18
Answer:
observational study
Step-by-step explanation:
This situation calls for an observational study. Unfortunately, cardiovascular health is difficult to measure unless one defines some "health scale" so that health could be roughly quantitized.
Answer:
11
Step-by-step explanation:
I'm assuming this is multiple choice and you forgot to post the answers. I'll take a guess and say it probably looks something like this:

Because you can't take the square root of a negative number without getting an imaginary result, resulting in the function having a closed domain limit.