Find the length of a line segment with endpoints of 19 and –39..
a.–58.
b.–20.
c.20.
d.58.

This question we do not have to over think. We can already answer this with out the help of the diagram. The diagram helps us see that this problem involves the number line. Positive and negative numbers are involved in the number line. 

Here how we can think about it: From the middle to the left the length is 39 and to the right it is 19. The length is then 58. 

You add 19+39 which will give you 58 it is d