Question 28572
Let me begin by defining Square of a Number
The square of a number is that number multiplied by itself
i.e{{{X^2 = X*X}}}
Similarly Cube of a number is that number multiplied by itself 3 times
i.e. If X is the number then {{{X^3 = X*X*X}}}

Now 27 = 3*3*3 thus we can say that 3 is the Cube Root of 27
Any number when raised to the power 1/n and then again raised to power n = the number itself
i.e. {{{1/n * n = 1}}}
but if it was say 2/n then it becomes {{{2/n * n = 2}}}
which now becomes the square of the number
thus {{{(27)^(2/3)= (3^3)^(2/3) =3^2 = 9}}}

Now can you do for the rest of the numbers?