Can someone me with this question ?

What is f(3) for the quadratic functionf(x)=2x2 + x – 12? f -3g 3h 6i. 9

Afarmer has a large field that is x feet in length. he wants to fence in a rectangular section in the middle of the field , leaving a length of 100 feet of open field behind each end of the fenced rectangle.he also wants the width of the fenced-in space to be 100 feet less than its length. find the expressions to represent the length and width of the fenced section of the field

At a book fair, joe bought 24 books at 3 for $5 and had $2 left. how much money did he have at first?