13. five plus <em>y</em> equal to negative two. y = -7
14. eight plus <em>h</em> equal to twelve. h = 4
15. negative thirteen plus four equal <em>n</em>. n = -9
 
        
             
        
        
        
Answer:
1/2
Step-by-step explanation:
Remaining fraction will be (1-3/8)=5/8
Given that in the second hour he delivered 4/5 of 5/8, then the fraction delivered in the second hour will be:
4/5 of 5/8
=4/5×5/8
=1/2
He delivered 1/2 (in fraction)
 
        
             
        
        
        
The answer will be Addition Problem
        
             
        
        
        
Write the hours as ratio
Carrie : Jerry
   2      :    5
Put this ratio in words, we say 'for every two hours Carrie takes to inspect a case, Jerry would need 5 hours'
Carrie has done 30 minutes on a case before taking a break. It means Carrie has 1.5 hours left on the case if she was to continue it. 
We need to work out the proportion of the time Jerry would take in comparison to 1.5 hours that Carrie would have taken.
First, we divide 2 by 1.5 ⇒ 

Then we divide 5 by 4/3 ⇒ 

 hours
Jerry would have taken 3.75 hours to finish the rest of the case