Hi there!
First, you need to find the quotient of 4 and 13, obviously.
4/13 is equal to roughly 0.308.
Those grouping symbols around it tell you that you need to find the absolute value.
Absolute value is how far away a number is from 0 on a number line. 3, for example has a absolute value of 3, and -6 has an absolute value of 6.
So, the absolute value of 4/13 is about 0.308.
Hope this helps. :)
-Spagoot
