What unit of measure is used for this?

What are the domain and range of the function? f(x) = -4 (sqrt)x

Jada has a monthly budget for her cell phone bill. last month she spent 120% of her budget, and the bill was 60$. what is jada’s monthly budget

Marcus and cody both leave the park at the same time, but in opposite directions. if cody travels 6 mph faster than marcus and after 4 hours they are 64 miles apart, how fast is each traveling? solve using rare times time = distance.