Final answer:
The expression √(-3(1-5x)) does not make sense for any value of the variable x in the set of real numbers.
Step-by-step explanation:
The expression √(-3(1-5x)) involves taking the square root of a negative number, which is not defined in the set of real numbers. In mathematics, the square root of a negative number is represented as an imaginary number. Therefore, this expression does not make sense for any value of the variable x in the set of real numbers.