Solve the equation.

     `x^3-9 x^2-81 x+729=0`

`x^3-9 x^2-81 x+729=0=`  
(Use a comma to separate answers as needed.)

Box 1: Enter your answer as a list of values separated by commas: Example: -4, 3, 2
Enter each value as a number (like 5, -3, 2.2172) or as a calculation (like 5/3, 2^3, 5+4)
Enter DNE for Does Not Exist, oo for Infinity