Answer:
x = 19
Step-by-step explanation:
[tex]\sqrt[2]{x-3^3}[/tex] = 64
[tex]\sqrt[2]{x-3^3}[/tex] = 4³
multiply each side by the exponent 2/3 so the radical sign on left is removed
([tex]\sqrt[2]{x-3^3}[/tex])^2/3 = (4³)^2/3
x - 3 = 4²
x - 3 = 16
x = 19