What's -18÷(1-4+-2-4) explain pls need help​

The depth of a lake at a certain point, wich is a function of the distance of that point from shore, is 30 feet.

Which of the following are parts of a sphere

Amuffin recipe, which yields 12 muffins, calls for cup of milk for every 1 cups of flour. the same recipe calls for cup of coconut for every cup of chopped apple. to yield a batch of 30 muffins, how much flour will be needed in the mix?