Which one of the following statements gives the absolute value of the floating-point number x = -25.50?

The statement that correctly computes the absolute value of the floating-point number ( x = -25.50 ) is the one that uses the Math class. In many programming languages, including JavaScript and Java, the Math class includes a method specifically designed to return the absolute value of a number, which is denoted as Math.abs(x).

This method works by taking a numeric argument and returning the non-negative value of that number, regardless of whether the initial value is positive or negative. In the case of ( x = -25.50 ), using Math.abs(x) would yield 25.50, which is the expected outcome for an absolute value operation.

Other options do not correctly reference the necessary methods or functions required for finding the absolute value. For instance, while abs(x) could work in some contexts (like Python), it may not be universally applied across all programming languages without the Math qualifier. The expressions x.abs() and x.absolute() imply that the floating-point number instance itself has a method defined for this purpose, which is typically not the case in standard libraries. Thus, using Math.abs(x) is the most appropriate and universally accepted way to obtain the absolute value of a number in environments that adhere to this syntax.