Well Emily, i believe it is B.
To rewrite as a function of x (f(x)), write the equation so that y is by itself on one side of the equal sign and an expression involving only x is on the other side.
f (x) = - x^4
Answer: -8
Step-by-step explanation: When it says f(x), all you have to do is find value x on the coordinate plane and look up or down until you find a point that runs through that x value. In this case, if you draw a line on x=5, you can see that it goes across a point that has a y value of -8, which is your answer.
It can be written as 12/100
or reduced to 6/50
or reduced even further to 3/25