What is 1.8 in written notation

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?

The sum of two numbers is 86, and their difference is 20. find the two numbers

If (17, 4) is an ordered pair of the inverse of f(x), which of the following is an ordered pair of the function f(x)? a. (17,4) b. (4.17) c. (4,0) d. 0,17)