Many equations can also be solved by repeatedly applying a discrete-time dynamical system. Compare the following discrete-time

Question:

Many equations can also be solved by repeatedly applying a discrete-time dynamical system. Compare the following discrete-time dynamical systems with the Newton's method discrete-time dynamical system. Show that each has the same equilibrium, and see how close you get in three steps.
Use the discrete-time dynamical system xt+1 = x3t + xt - 20 to solve x3 = 20.