Question 242781
Your question is not clear.  The description you gave of the "square root" but with a 3 in in the radical is the "cube root" not the square root.  The cube root of 27 is 3, which is 3*3*3, which is shown as 3^3.

If the (4+6t) has a little 3 exponent, then it is to the third power and the cube root is simply 4+6t.  But I cannot say for sure from your description.