
Cube root each side.
∛5832 = 18. You can prime factorize to find this.

Add 9 to each side.

Divide by 8.

Cube root each side.

Note that radicals with an odd index (cube roots, 5th, 7th, etc.) don't leave a plus-minus...If there's an even number all of the negatives cancel, but if it's odd, it won't, just as with exponents.