A should be the right answer because 4*5/4=5 + 5*2=10 and 5+10=15.
        
             
        
        
        
By what I can tell, that is telling you what the measurement of rain was per month.  For example, August had 10.  That means that in the month of August there was 10 inches of rain.
 
        
             
        
        
        
27+x simplify the expression
        
             
        
        
        
The first equation can be written as:
2x = 5 + 3y
Substituting the second equation into the first equation and rearranging:
-4y - 16 = 5 + 3y
-21 = 7y
y = -3
Substituting y = -3 into the second equation:
x = -2(-3) - 8
x = -2