Answer:
<h2>20</h2>
Step-by-step explanation:

 
        
             
        
        
        
Expected value of the bet is 
the sum of the products of value of outcome and its probability, 
less the amount paid to place the bet.
Outcomes value probability
win            225    1/4
lose               0    3/4
cost of bet = 40
So expected value of bet
E[X]=225*(1/4)+0*(3/4)-40
=56.25-40
=16.25
This means that in the long run, gambler will win, since the expected value is positive.  (does NOT mean she will win in the next bet!)
        
             
        
        
        
Answer:
y = -4x - 6
Step-by-step explanation:
12x + 3y = -18
Solve for y.
3y = -12x - 18
y = -12/3 x - 18/3
y = -4x - 6
 
        
                    
             
        
        
        
Answer:
Prime.
Step-by-step explanation:

First let's multiply our outer coefficients in this case 1 and 8, so we have 1x8=8.  Now the point of this is to get the factors of 8 and see if we can get that middle term -7.  Factors of 8 are 1x8, 2x4 and that's it.  From there I notice that -8+1 = -7 and so:

Notice that the (x-8) and (x+8) are not the same factors, therefore the factors are not any of those answer choices and so it's prime.  You can calculate the factors by using the quadratic formula, however I think that is beyond the scope of this question.
 
        
             
        
        
        
Answer:
9
Step-by-step explanation:
Let the no be x
 By the conditions given ,
2x + 6x = 72 
8x = 72
x = 72/8
x = 9
therefore the no is 9