[tex]216 + x = x(x {}^{2} - 5) + 6x[/tex]
[tex]216 + x = x {}^{3} - 5x + 6x[/tex]
Add like terms
[tex]216 + x = x {}^{3} + x[/tex]
Subtract x form both sides and they both cancel out
[tex]216 = x {}^{3} [/tex]
Subtract 216 from both sides
[tex]216 - x {}^{3} = 0[/tex]
Plug in your calculator, in your "y=" and look at your zeros and *check if they equal each other by substituting x with the zeros and that ones that work is your answer.
