Question

how do you solve.... x^3 -216=0 ??

Answer 1

Whenever you have an equation, you can do the same thing to both sides, and they will remain equal. So:
\[x^3 - 216 = 0\]
Now add 216 to both sides:
\[x^3 = 216\]
Finally take the cube root of both sides:
\[x = 6\]