For the function given by n(z) = ab + wz, what is the independent variable? How can you tell?

For the function given by n(z) = ab + wz, what is the independent variable? How can you tell?For the function given by n(z) = ab + wz, what is the independent variable? How can you tell?
z is the independent variable. The reason for this is becuase you have n(z) which translates of n as a function of z. Therefore, the value of n depends on the function of z.