Y = 7x^2-3
x=7y^2-3
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Use distance formula:-
distance =  sqrt  [ (x2 - x1)^2 + (y2 - y1)^2) ]
let (x1,y1) = (-3,1) and (x2,y2) = (-1,6)   Plug these values in to formula.
        
             
        
        
        
The reaction is missing and it's ;
N2H4 + H2 ---> 2NH3
It asks for the total pressure too. 
Answer:
A) Rate of change for NH3 = 152 torr/h
B) The total pressure in the vessel will remain the same. 
Step-by-step explanation:
N2H4 + H2 ---> 2NH3 
1 mole of N2H4 yields 2 moles of NH3. 
From the question, the rate given for N2H4 is 76 torr/h.
Thus, The rate of change for NH3 will be = 2 x 76 = 152 torr/h
Now, on the reaction side, 1 mole of N2H4 reacts with 1 mole of H2. So we have 2 moles on the left hand side. 
While on the product side, 2 moles of NH3 are produced.
So the total pressure will remain the same because for every 2 moles on the reaction side, 2 moles are gotten on the product side. 
 
        
             
        
        
        
C hope it helps .....................