Answer: |y-x|
Step-by-step explanation:
The absolute value of a real number (also called modulus) is a "non-negative value of that number without regard to its sign". This is because absolute values are, in fact, distances.
In other words: An absolute value is a number's distance from zero in the Number line.
For example, the absolute value of 7 is 7, and the absolute value of −7 is also 7!
Now, in the case of |x-y|, this is equal to |-x+y|:
|x-y|=|-x+y|=|y-x|
We can prove it with any two real numbers. For example, x=1 and y=2:
|1-2|=|-1|=1
|-1+2|=|1|=1
Therefore the expression |x − y| is always equivalent to |y − x|