Which of the following is always true for any real number 'a' and 'b'?  Choose the correct choice from the following.
A) |ab| = |a||b| B) |a/b| = |a|/|b| C) |-ab| < |a||b| D) |ab| > |a/b| E) |ab| = -|ab|
This one is obvious if you know how absolute value works. One of the fundamental principles of absolute value is multiplicativeness, which holds that for absolute values, f(ab) = f(a) f(b). Thus the answer is |ab| = |a||b|.
<result>A</result>
Which of the following is always true for any real number 'a' and 'b'?