To set up a problem to use solver, you need to do two things.  First, put the starting values on the Excel sheet in a column vector and second type in you equation in the form of a formula of the starting values.

START SOLVER

You then need to go to the tools menu and select solver.  You will get the dialog pictured below.  Set the target cells to be the starting cells and the By Changing Cells to be the function.  Then select Max of Min and hit solve.

FINISHED

When Solver finished, you will see the dialog below.  You can check this answer against the answers you calculated using Newton-Raphson or Steepest Decent.