Remember (x^m)(x^n)=x^(m+n) and difference of 2 perfect squres (a²-b²)=(a-b)(a+b) and sum or difference of 2 perfect cubes
so (x^3)(x^3)(x^3)=x^(3+3+3)=x^9 so
x^9=3*3*x^3 x^9=9x^3 minus 9x^3 both sides 0=x^9-9x^3 factor 0=(x^3)(x^6-9) factor difference of 2 perfect squraes 0=(x^3)(x^3-3)(x^3+3) factor differnce or sum of 2 perfect cubes (force 3 into (∛3)³) 0=(x³)(x-∛3)(x²+x∛3+∛9)(x+∛3)(x²-x∛3+∛9) set each to zero