Make a the subject of the formula in: p - a = ar/100

One expression below in undefined, and the other expression has a well defined value. which expression is undefined and explain why it has no value. which expression is defined? what is the value of that expression and how do you know? what is a different expression using a trig inverse function that is also undefined?

What are the possible rational zeros of [tex]f(x) = x^4+2x^3-3x^2-4x+18[/tex]

What is the slope of the line that passes through the points (–9, 2) and (0, 4)? the slope of the line is