if f(x) = 4x-3, find the following

  f(-1)

These are function notation problems.

Please help

You will find this to be real easy.

Notice the difference between
the notations " f(x) " and " f(-1)".
The first one has an x in the 
parentheses and the second one has
a -1 in the parentheses. This means
that you substitute (-1) for x in
the right side of f(x).

  f( x) = 4x    - 3

  f(-1) = 4(-1) - 3
  
Then you simplify the right side:

  f(-1) = -4 - 3
  f(-1) = -7

So the function notation just has
a parentheses in which you put the
number you have to substitute for x.

Whatever you see in the parentheses
of "f(  )", that's what you are to
substitute for x in the right side.
This is probably one of the easiest
things you'll study in math.

Edwin