Step-by-step explanation:
I think you mean that 10 cm³ of air are escaping every second. 
and we start with a volume of 500 cm³.
V = 500 - 10t 0 <= t <= 50
because negative t (seconds) don't make any sense, and neither does a negative volume (for t > 50). 
 
        
             
        
        
        
It's B
Slope is negative, the other must be positive due to m1 x m2 = - 1
m1 = -2/5
The diagram shows a gradient of -2/5. So, the
reciprocal of this valve to make - 1 is 5/2 (which is the - 2/5 flipped upside down, but positive) 
-2/5 x 5/2 = - 10/10 (or - 1)
Thus, the perpendicular line to this has a gradient of 5/2.
Hope this helps! 
 
        
             
        
        
        
Answer: Hope this helps you.
-2
Step-by-step explanation:
y = mx+b (B is y-int)
y = 4^x-2
-2 is clearly replacing the b (y-int) meaning b, the y-int, is -2
 
        
                    
             
        
        
        
Answer:
12000
Step-by-step explanation:
1200=100
x=1000
x=100*1200/100
 
        
             
        
        
        
Answer:
219.6 days
Step-by-step explanation: