The points on the graph ( b , c )
 I hope I helped you ^_^
 
        
             
        
        
        
Janet can fill a certain order in 5 hours, therefore she performs 1/5 of the order within 1 hour.
Tom needs 8 hours to do the same job, therefore he performs 1/8 of the order within 1 hour.
Working together, they make 1/5 + 1/8 orders within 1 hour.
Let <em>t</em> mean the number of hours they need. Then we have equation:

 
        
             
        
        
        
Answer:
12+8r
Step-by-step explanation:
2(6+4r) = 30r
If I am wrong, please let me know and I will do a re-correction
 
        
             
        
        
        
In algebra it is fully possible for x to equal to zero. After you have 2x, just divide both sides by two, so it would be 2 divided by 0 and than you would have x=0 and that would be your final answer.
2x + 1 = 4x +1
-2x +1 = 1
-2x = 0
divide by -2 
x=0
        
             
        
        
        
The rise or an increase in altitude is represented by positive sign and a decend or decrease in altitude is represented by negative sign. 
First the helicopter descended 1200 feet. So the change in altitude will be -1200 feet.
Then the helicopter rose by 800 feet. So the change in altitude will be 800 feet.
Finally the helicopter descended by 450 feet. So the change in altitude will be -450 feet.
The net change in altitude will be the sum of all the above 3 changes. 
Change in altitude = -1200 + 800 - 450 = -850 feet
The negative sign indicates a descend i.e. loss in altitude. So the net change in altitude was a loss of 850 feet.