Question 1053105
the number is x
x^3+9=81x
x^3-81x+9=0
{{{graph(300,300,-10,10,-100,100,x^3-81x+9)}}}
0.111128 is one zero; cube of that plus 9=9.0014.  0.111128*81 is 9.0014
-9.055 is a second zero. Cube of that +9 is -733.45,  -9.055*81 is -733.46
8.9439 is the third zero.  Cube that and add 9 and get 724.452  8.9439*81 is 724.456