HELP ME PLEASE THIS IS RIGHT ONE DONT GIVE WRONG ANSWER PLS 3

What is f(3) for the quadratic function f(x)= 2x^2+ + x - 12

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?

Evaluate the expression for the given value of the variable 7a - 4a for a =8