Question 704836
Let's ignore the negative sign for the moment!
{{{3sqrt(1/152)}}} is the same as
{{{3sqrt(1)/(3sqrt(512))}}}
the cube root of 1 is 1 and the cube root of 512 is 8 so 
{{{3sqrt(1/152)=(1/8)}}}
Now about the negative sign... a square root can have two values, positive or negative, but a cube root can only have 1 value!
Because this is a negative number the answer will be negative
So the answer is {{{-(1/8)}}}